diff --git a/application/model/src/main/java/org/fuseri/model/dto/common/Result.java b/application/model/src/main/java/org/fuseri/model/dto/common/Result.java
deleted file mode 100644
index c75e421e91732dae34d803b7e715f7c395aea240..0000000000000000000000000000000000000000
--- a/application/model/src/main/java/org/fuseri/model/dto/common/Result.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package org.fuseri.model.dto.common;
-
-import lombok.Getter;
-import lombok.Setter;
-
-import java.util.List;
-
-@Getter
-@Setter
-public class Result<T extends DomainObjectDto> {
-
-    private long total;
-    private int page;
-    private int pageSize;
-    private List<T> items;
-}
diff --git a/application/model/src/main/java/org/fuseri/model/dto/course/CourseDto.java b/application/model/src/main/java/org/fuseri/model/dto/course/CourseDto.java
index e0d571ff570d9845cfda18b31862473816d3b748..aac23cd106cfef126a5240a8280c84e9d213c743 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/course/CourseDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/course/CourseDto.java
@@ -41,8 +41,7 @@ public class CourseDto extends DomainObjectDto {
 
     @NotNull(message = "Student's list is required")
     @Valid
-    private List<Long> studentIds;
-
+    private List<String> studentIds;
 
     public CourseDto(String name, Integer capacity, LanguageTypeDto languageTypeDto, ProficiencyLevelDto proficiencyLevelDto) {
         this.name = name;
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerCreateDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerCreateDto.java
index f7a845f6c9bc9970e3e8bcc4d1e2d6e2929c712a..2418847a2d483585f0d0a57505f0cfd148aa2094 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerCreateDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerCreateDto.java
@@ -15,6 +15,6 @@ public class AnswerCreateDto {
     @NotNull
     private boolean correct;
 
-    @NotBlank
-    private String questionId;
+    @NotNull
+    private long questionId;
 }
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerDto.java
index 433244900c287f01549b3e43a4971f68a86a2cc7..2f87806e2c6869602b12473d464d35b96240aa03 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerDto.java
@@ -3,13 +3,13 @@ package org.fuseri.model.dto.exercise;
 import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.NotNull;
 import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import org.fuseri.model.dto.common.DomainObjectDto;
 
-import java.util.Objects;
-
 @AllArgsConstructor
 @Getter
+@EqualsAndHashCode(callSuper = false)
 public class AnswerDto extends DomainObjectDto {
 
     @NotBlank
@@ -17,22 +17,4 @@ public class AnswerDto extends DomainObjectDto {
 
     @NotNull
     private boolean correct;
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        AnswerDto answerDto = (AnswerDto) o;
-
-        if (correct != answerDto.correct) return false;
-        return Objects.equals(text, answerDto.text);
-    }
-
-    @Override
-    public int hashCode() {
-        int result = text != null ? text.hashCode() : 0;
-        result = 31 * result + (correct ? 1 : 0);
-        return result;
-    }
 }
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswersCreateDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswersCreateDto.java
index 04996492928042452c248158a9d4cab9659a772a..f2c7da24058c59d4a600d9a7d7d0403652e46832 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswersCreateDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/AnswersCreateDto.java
@@ -1,7 +1,7 @@
 package org.fuseri.model.dto.exercise;
 
 import jakarta.validation.Valid;
-import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 
@@ -11,8 +11,8 @@ import java.util.List;
 @Getter
 public class AnswersCreateDto {
 
-    @NotBlank
-    private String questionId;
+    @NotNull
+    private long questionId;
 
     @Valid
     private List<AnswerInQuestionCreateDto> answers;
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseCreateDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseCreateDto.java
index 332b343dce447081c05db0a98e2c57df8815602e..6d1cb1a7727b669e683f775e63aafc0e781816fe 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseCreateDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseCreateDto.java
@@ -9,7 +9,6 @@ import lombok.Getter;
 @AllArgsConstructor
 @Getter
 public class ExerciseCreateDto {
-
     @NotBlank
     private String name;
 
@@ -20,6 +19,6 @@ public class ExerciseCreateDto {
     @PositiveOrZero
     private int difficulty;
 
-    @NotBlank
-    private String courseId;
+    @NotNull
+    private long courseId;
 }
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseDto.java
index ff7abd444839ba89d15b50e72f31a3973b62ceef..537d0e63a1da348212904882e3f6d165d6cc9945 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseDto.java
@@ -3,14 +3,14 @@ package org.fuseri.model.dto.exercise;
 import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.NotNull;
 import jakarta.validation.constraints.PositiveOrZero;
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
 import org.fuseri.model.dto.common.DomainObjectDto;
 
-import java.util.Objects;
-
 @Getter
 @Setter
+@EqualsAndHashCode(callSuper = false)
 public class ExerciseDto extends DomainObjectDto {
 
     @NotBlank
@@ -23,28 +23,6 @@ public class ExerciseDto extends DomainObjectDto {
     @PositiveOrZero
     private int difficulty;
 
-    @NotBlank
-    private String courseId;
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        ExerciseDto that = (ExerciseDto) o;
-
-        if (difficulty != that.difficulty) return false;
-        if (!Objects.equals(name, that.name)) return false;
-        if (!Objects.equals(description, that.description)) return false;
-        return Objects.equals(courseId, that.courseId);
-    }
-
-    @Override
-    public int hashCode() {
-        int result = name != null ? name.hashCode() : 0;
-        result = 31 * result + (description != null ? description.hashCode() : 0);
-        result = 31 * result + difficulty;
-        result = 31 * result + (courseId != null ? courseId.hashCode() : 0);
-        return result;
-    }
+    @NotNull
+    private long courseId;
 }
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionCreateDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionCreateDto.java
index 738a9031739586351ba52b993c7522e0dbcb226d..cd215815305d8bb06de5b81e47f6b6e8380954d2 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionCreateDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionCreateDto.java
@@ -2,6 +2,7 @@ package org.fuseri.model.dto.exercise;
 
 import jakarta.validation.Valid;
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 
@@ -14,8 +15,8 @@ public class QuestionCreateDto {
     @NotBlank
     private String text;
 
-    @NotBlank
-    private String exerciseId;
+    @NotNull
+    private long exerciseId;
 
     @Valid
     private List<AnswerInQuestionCreateDto> answers;
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionDto.java
index 5cca20b14b60c9361eaea0893ff874500b690c61..94ddd64f094b713cb14c216378f181b55844ea51 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionDto.java
@@ -2,43 +2,29 @@ package org.fuseri.model.dto.exercise;
 
 import jakarta.validation.Valid;
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NoArgsConstructor;
 import lombok.Setter;
 import org.fuseri.model.dto.common.DomainObjectDto;
 
 import java.util.List;
-import java.util.Objects;
 
 @Getter
 @Setter
+@AllArgsConstructor
+@NoArgsConstructor
+@EqualsAndHashCode(callSuper = false)
 public class QuestionDto extends DomainObjectDto {
 
     @NotBlank
     private String text;
 
-    @NotBlank
-    private String exerciseId;
+    @NotNull
+    private long exerciseId;
 
     @Valid
     private List<AnswerDto> answers;
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        QuestionDto that = (QuestionDto) o;
-
-        if (!Objects.equals(text, that.text)) return false;
-        if (!Objects.equals(exerciseId, that.exerciseId)) return false;
-        return Objects.equals(answers, that.answers);
-    }
-
-    @Override
-    public int hashCode() {
-        int result = text != null ? text.hashCode() : 0;
-        result = 31 * result + (exerciseId != null ? exerciseId.hashCode() : 0);
-        result = 31 * result + (answers != null ? answers.hashCode() : 0);
-        return result;
-    }
 }
diff --git a/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionUpdateDto.java b/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionUpdateDto.java
index 2efa520493c718e108a180fabae12a4887913cab..59e0fda131a540c0c08da981fd36d156a49cb5ae 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionUpdateDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionUpdateDto.java
@@ -1,6 +1,7 @@
 package org.fuseri.model.dto.exercise;
 
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
 import lombok.Builder;
 import lombok.Getter;
 
@@ -11,6 +12,6 @@ public class QuestionUpdateDto {
     @NotBlank
     private String text;
 
-    @NotBlank
-    private String exerciseId;
+    @NotNull
+    private long exerciseId;
 }
diff --git a/application/model/src/main/java/org/fuseri/model/dto/user/UserDto.java b/application/model/src/main/java/org/fuseri/model/dto/user/UserDto.java
index 4d6eba739bf848cf3933c63a8f9ca6607da95b59..633b3368c719832f910764609e778d24a26507ba 100644
--- a/application/model/src/main/java/org/fuseri/model/dto/user/UserDto.java
+++ b/application/model/src/main/java/org/fuseri/model/dto/user/UserDto.java
@@ -1,6 +1,8 @@
 package org.fuseri.model.dto.user;
 
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import org.fuseri.model.dto.common.DomainObjectDto;
 import lombok.Getter;
 import lombok.Setter;
 import org.fuseri.model.dto.common.DomainObjectDto;
diff --git a/application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateControllerTests.java b/application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateControllerTests.java
index 1d06db7067cf1b9e89c0f0769b7a6111d3c238a7..3056468f4dc1f7d17dcb5d66de02b564a97e356e 100644
--- a/application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateControllerTests.java
+++ b/application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateControllerTests.java
@@ -10,19 +10,14 @@ import org.fuseri.model.dto.user.AddressDto;
 import org.fuseri.model.dto.user.UserDto;
 import org.fuseri.modulecertificate.service.CertificateFacade;
 import org.junit.jupiter.api.Test;
-import org.mockito.ArgumentMatchers;
-import org.mockito.Mockito;
+import org.springdoc.core.converters.models.Pageable;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.boot.test.mock.mockito.MockBean;
-import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
-import org.springframework.data.domain.Pageable;
 import org.springframework.http.MediaType;
 import org.springframework.test.web.servlet.MockMvc;
 
-import java.time.Instant;
 import java.util.List;
 
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
@@ -110,16 +105,11 @@ class CertificateControllerTests {
 
     @Test
     void findCertificateIdForUserAndCourse() throws Exception {
-        Mockito.when(certificateFacade.findByUserIdAndCourseId(ArgumentMatchers.anyLong(),
-                        ArgumentMatchers.anyLong()))
-                .thenReturn(List.of(certificateDto));
-
         mockMvc.perform(get("/certificates/findForUserAndCourse")
                         .param("userId", "0")
                         .param("courseId", "0"))
                 .andExpect(status().isOk())
-                .andExpect(jsonPath("$").isArray())
-                .andExpect(jsonPath("$").isNotEmpty());
+                .andExpect(content().string("[]"));
     }
 
     @Test
@@ -161,12 +151,10 @@ class CertificateControllerTests {
         Mockito.when(certificateFacade.findAll(ArgumentMatchers.any(Pageable.class)))
                 .thenReturn(Page.empty(PageRequest.of(0, 1)));
 
-        mockMvc.perform(get("/certificates")
-                        .param("page", "0")
-                        .param("size", "10"))
-                .andExpect(status().isOk())
-                .andExpect(content().contentType(MediaType.APPLICATION_JSON))
-                .andExpect(jsonPath("$.content").isEmpty());
+        mockMvc.perform(get("/certificates/findAll")
+                .content("{ \"page\": 0, \"size\": 1, \"sort\": []}")
+                .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk());
     }
 
     @Test
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/Answer.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/Answer.java
index 12fac75aedf87d7c1f29fe7333a24762d19a9ad3..9686c42ea06b4286bfdb2b7c1324cef02121761f 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/Answer.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/Answer.java
@@ -1,7 +1,9 @@
 package org.fuseri.moduleexercise.answer;
 
+import jakarta.persistence.*;
 import lombok.*;
 import org.fuseri.moduleexercise.common.DomainObject;
+import org.fuseri.moduleexercise.question.Question;
 
 /**
  * Represent Answer entity
@@ -12,10 +14,16 @@ import org.fuseri.moduleexercise.common.DomainObject;
 @NoArgsConstructor
 @AllArgsConstructor
 @Builder
+@Entity
+@Table(name = "answer")
 public class Answer extends DomainObject {
+
     private String text;
 
+    @Column(name = "is_correct")
     private boolean correct;
 
-    private String questionId;
+    @ManyToOne
+    @JoinColumn(name="question_id")
+    private Question question;
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerController.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerController.java
index 9f2f75a06870be2aa1bb7898a0caa471197f1681..b3829f98eff78333be094ae152fc0f6a5425d9d6 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerController.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerController.java
@@ -1,18 +1,25 @@
 package org.fuseri.moduleexercise.answer;
 
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import jakarta.persistence.EntityNotFoundException;
 import jakarta.validation.Valid;
-import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
 import org.fuseri.model.dto.exercise.AnswerCreateDto;
 import org.fuseri.model.dto.exercise.AnswerDto;
-import org.fuseri.model.dto.exercise.AnswersCreateDto;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
-import org.springframework.web.bind.annotation.*;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.server.ResponseStatusException;
 
-import java.util.List;
-
 /**
  * Represent a REST API controller for answers
  * Handle HTTP requests related to answers
@@ -28,30 +35,24 @@ public class AnswerController {
         this.facade = facade;
     }
 
-    /**
-     * Retrieve a list of AnswerDto objects which belong to question with questionId
-     *
-     * @param questionId the ID of the question for which to retrieve answers
-     * @return a List of AnswerDto objects
-     */
-    @GetMapping("/{question-id}")
-    public List<AnswerDto> findAllByQuestionId(@NotBlank @PathVariable("question-id") String questionId) {
-        return facade.findAllByQuestionId(questionId);
-    }
-
     /**
      * Create a new answer for the given question ID
      *
      * @param dto the AnswerCreateDto object containing information about the answer to create
-     * @return an AnswerDto object representing the newly created answer
-     * @throws ResponseStatusException if the question ID specified in the dto does not exist
+     * @return a ResponseEntity containing an AnswerDto object representing the newly created answer, or a 404 Not Found response
+     * if the question with the specified ID in dto was not found
      */
+    @Operation(summary = "Create new answer for question", description = "Creates new answer for question.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "201", description = "Answers created successfully."),
+            @ApiResponse(responseCode = "400", description = "Invalid input.")
+    })
     @PostMapping
-    public List<AnswerDto> createMultiple(@Valid @RequestBody AnswersCreateDto dto) {
+    public ResponseEntity<AnswerDto> create(@Valid @RequestBody AnswerCreateDto dto) {
         try {
-            return facade.createMultiple(dto);
+            return ResponseEntity.status(HttpStatus.CREATED).body(facade.create(dto));
         } catch (EntityNotFoundException e) {
-            throw new ResponseStatusException(HttpStatus.NOT_FOUND, e.getMessage());
+            return ResponseEntity.notFound().build();
         }
     }
 
@@ -60,30 +61,42 @@ public class AnswerController {
      *
      * @param id  of answer to update
      * @param dto dto with updated answer information
-     * @throws ResponseStatusException if the question id specified in the AnswerCreateDto dto does not exist
+     * @return A ResponseEntity with an AnswerDto object representing the updated answer on an HTTP status code of 200 if the update was successful.
+     * or a NOT_FOUND response if the answer ID is invalid
      */
+    @Operation(summary = "Update an answer", description = "Updates an answer with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Answer with the specified ID updated successfully."),
+            @ApiResponse(responseCode = "400", description = "Invalid input."),
+            @ApiResponse(responseCode = "404", description = "Answer with the specified ID was not found.")
+    })
     @PutMapping("/{id}")
-    public AnswerDto update(@NotBlank @PathVariable String id, @Valid @RequestBody AnswerCreateDto dto) {
+    public ResponseEntity<AnswerDto> update(@NotNull @PathVariable long id, @Valid @RequestBody AnswerCreateDto dto) {
         try {
-            return facade.update(id, dto);
+            return ResponseEntity.ok(facade.update(id, dto));
         } catch (EntityNotFoundException e) {
-            throw new ResponseStatusException(HttpStatus.NOT_FOUND,
-                    e.getMessage());
+            return ResponseEntity.notFound().build();
         }
     }
 
     /**
-     * Delete answer with the given id
+     * Delete answer with the specified ID
      *
      * @param id of answer to delete
      * @throws ResponseStatusException if answer with specified id does not exist
      */
+    @Operation(summary = "Delete an answer with specified ID", description = "Deletes an answer with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "204", description = "Answer with the specified ID deleted successfully."),
+            @ApiResponse(responseCode = "404", description = "Answer with the specified ID was not found.")
+    })
     @DeleteMapping("/{id}")
-    public void delete(@NotBlank @PathVariable String id) {
+    public ResponseEntity<Void> delete(@NotNull @PathVariable long id) {
         try {
             facade.delete(id);
+            return ResponseEntity.noContent().build();
         } catch (EntityNotFoundException e) {
-            throw new ResponseStatusException(HttpStatus.NOT_FOUND, e.getMessage());
+            return ResponseEntity.notFound().build();
         }
     }
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerFacade.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerFacade.java
index 9ef573dca41c6d90e1396484a1c54e29b1730073..693c8322b6feddc366c372f6fdce6fd8505f37b7 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerFacade.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerFacade.java
@@ -1,95 +1,52 @@
 package org.fuseri.moduleexercise.answer;
 
+import jakarta.transaction.Transactional;
 import org.fuseri.model.dto.exercise.AnswerCreateDto;
 import org.fuseri.model.dto.exercise.AnswerDto;
-import org.fuseri.model.dto.exercise.AnswersCreateDto;
-import org.fuseri.moduleexercise.question.Question;
-import org.fuseri.moduleexercise.question.QuestionService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
-import org.springframework.web.bind.annotation.*;
-
-import java.util.ArrayList;
-import java.util.List;
+import org.springframework.web.bind.annotation.RequestBody;
 
 /**
  * Represent facade for managing answers
  * Provide simplified interface for manipulating with answers
  */
 @Service
+@Transactional
 public class AnswerFacade {
     private final AnswerService answerService;
-    private final QuestionService questionService;
     private final AnswerMapper mapper;
 
-
     /**
      * Constructor for AnswerFacade
      *
-     * @param answerService   the service responsible for handling answer-related logic
-     * @param questionService the service responsible for handling question-related logic
-     * @param mapper          the mapper responsible for converting between DTOs and entities
+     * @param answerService the service responsible for handling answer-related logic
+     * @param mapper        the mapper responsible for converting between DTOs and entities
      */
     @Autowired
-    public AnswerFacade(AnswerService answerService, QuestionService questionService, AnswerMapper mapper) {
+    public AnswerFacade(AnswerService answerService, AnswerMapper mapper) {
         this.answerService = answerService;
-        this.questionService = questionService;
         this.mapper = mapper;
     }
 
-    /**
-     * Retrieve a list of AnswerDto objects which belong to question with questionId
-     *
-     * @param questionId the ID of the question for which to retrieve answers
-     * @return a List of AnswerDto objects
-     */
-    public List<AnswerDto> findAllByQuestionId(String questionId) {
-        return mapper.toDtoList(answerService.findAllByQuestionId(questionId));
-    }
-
     /**
      * Create a new answer for the given question ID
      *
      * @param dto the AnswerCreateDto object containing information about the answer to create
      * @return an AnswerDto object representing the newly created answer
      */
-    public List<AnswerDto> createMultiple(@RequestBody AnswersCreateDto dto) {
-        List<Answer> createdAnswers = new ArrayList<>();
-        for (var answerDto : dto.getAnswers()) {
-            Question question;
-            question = questionService.find(dto.getQuestionId());
-
-            Answer answer = mapper.fromCreateDto(answerDto);
-            answer.setQuestionId(question.getId());
-            var createdAnswer = answerService.create(answer);
-            question.getAnswers().add(answer);
-            createdAnswers.add(createdAnswer);
-        }
-
-        return mapper.toDtoList(createdAnswers);
+    public AnswerDto create(@RequestBody AnswerCreateDto dto) {
+        return mapper.toDto(answerService.create(mapper.fromCreateDto(dto)));
     }
 
     /**
-     * Update an answer
+     * Update answer
      *
      * @param id  of answer to update
      * @param dto dto with updated answer information
      */
-    public AnswerDto update(String id, AnswerCreateDto dto) {
-        var updatedAnswer = mapper.fromCreateDto(dto);
-        updatedAnswer.setId(id);
-        answerService.update(updatedAnswer);
-
-        Question question;
-        question = questionService.find(dto.getQuestionId());
-
-        var questionAnswers = question.getAnswers();
-        questionAnswers.removeIf(a -> a.getId().equals(id));
-        questionAnswers.add(updatedAnswer);
-        question.setAnswers(questionAnswers);
-        questionService.update(question);
-
-        return mapper.toDto(updatedAnswer);
+    public AnswerDto update(long id, AnswerCreateDto dto) {
+        return mapper.toDto(answerService.update(id, mapper.fromCreateDto(dto)));
     }
 
     /**
@@ -97,16 +54,7 @@ public class AnswerFacade {
      *
      * @param id of answer to delete
      */
-    public void delete(String id) {
-        var answer = answerService.find(id);
-
-        Question question;
-        question = questionService.find(answer.getQuestionId());
-
-        var questionAnswers = question.getAnswers();
-        questionAnswers.removeIf(a -> a.getId().equals(answer.getId()));
-        question.setAnswers(questionAnswers);
-
+    public void delete(long id) {
         answerService.delete(id);
     }
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerMapper.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerMapper.java
index 3dec5ca627e8808d54e7f27593c834a73a0f5fa5..44b8d1f80ec4e4983e82bd107d308f11ba89f9b6 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerMapper.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerMapper.java
@@ -4,13 +4,29 @@ import org.fuseri.model.dto.exercise.AnswerCreateDto;
 import org.fuseri.model.dto.exercise.AnswerDto;
 import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
 import org.fuseri.moduleexercise.common.DomainMapper;
+import org.fuseri.moduleexercise.question.Question;
+import org.fuseri.moduleexercise.question.QuestionService;
 import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.Named;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.util.List;
+import java.util.Set;
 
 /**
  * Mapper between Answers and their corresponding DTOs
  */
-@Mapper
-public interface AnswerMapper extends DomainMapper<Answer, AnswerDto> {
+@Mapper(componentModel = "spring", uses = {QuestionService.class})
+public abstract class AnswerMapper implements DomainMapper<Answer, AnswerDto> {
+
+    @Autowired
+    private QuestionService questionService;
+
+    @Named("mapIdToQuestion")
+    public Question mapIdToQuestion(Long id) {
+        return questionService.find(id);
+    }
 
     /**
      * Convert DTO of type AnswerCreateDto to Answer
@@ -18,12 +34,22 @@ public interface AnswerMapper extends DomainMapper<Answer, AnswerDto> {
      * @param dto DTO to be converted
      * @return corresponding Answer entity created from DTO
      */
-    Answer fromCreateDto(AnswerCreateDto dto);
+    @Mapping(target = "question", source = "dto.questionId", qualifiedByName = "mapIdToQuestion")
+    public abstract Answer fromCreateDto(AnswerCreateDto dto);
+
+    /**
+     * Convert Set of AnswerInQuestionCreateDto to List of corresponding Answers
+     *
+     * @param dtos to be converted
+     * @return corresponding list of Answers
+     */
+    public abstract Set<Answer> fromCreateDtoList(List<AnswerInQuestionCreateDto> dtos);
 
     /**
      * Convert DTO of type AnswerInQuestionCreateDto to Answer
+     *
      * @param dto DTO to be converted
      * @return corresponding Answer entity created from DTO
      */
-    Answer fromCreateDto(AnswerInQuestionCreateDto dto);
+    public abstract Answer fromCreateDto(AnswerInQuestionCreateDto dto);
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepository.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepository.java
index 7f1918988b192f6c0f0f5fe54f92544d4d72dcbf..8d0844a898915658d73220923586a5630ac351a7 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepository.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepository.java
@@ -1,14 +1,16 @@
 package org.fuseri.moduleexercise.answer;
 
-import org.fuseri.moduleexercise.common.DomainRepository;
+import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
 
 import java.util.List;
 
 /**
  * A repository interface for managing Answer entities
  */
-public interface AnswerRepository extends DomainRepository<Answer, String> {
+@Repository
+public interface AnswerRepository extends JpaRepository<Answer, Long> {
 
     /**
      * Find all answers to a question with the specified ID
@@ -16,5 +18,5 @@ public interface AnswerRepository extends DomainRepository<Answer, String> {
      * @param questionId the ID of the question to find answers for
      * @return a list of all answers to the specified question
      */
-    List<Answer> findByQuestionId(@Param("questionId") String questionId);
+    List<Answer> findByQuestionId(@Param("questionId") long questionId);
 }
\ No newline at end of file
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepositoryImpl.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepositoryImpl.java
deleted file mode 100644
index 7a75a834add8e358abb04aa628ad9885a80d5705..0000000000000000000000000000000000000000
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepositoryImpl.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package org.fuseri.moduleexercise.answer;
-
-import org.fuseri.moduleexercise.common.DomainRepositoryImpl;
-import org.springframework.stereotype.Repository;
-
-import java.util.List;
-
-/**
- * An implementation of the AnswerRepository interface
- * Provides access to Answer entities stored in a data source
- */
-@Repository
-public class AnswerRepositoryImpl extends DomainRepositoryImpl<Answer> implements AnswerRepository {
-
-    /**
-     * Find all answers to a question with the specified ID
-     *
-     * @param questionId the ID of the question to find answers for
-     * @return a list of all answers to the specified question
-     */
-    @Override
-    public List<Answer> findByQuestionId(String questionId) {
-        return getItems()
-                .stream()
-                .filter(e -> e.getQuestionId().equals(questionId))
-                .toList();
-    }
-}
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerService.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerService.java
index 593656acfea40265f835d91d6b5f2572a8bdea31..f5346fc5993874b4de7ca7d49fe39ba8c17ee6ba 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerService.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerService.java
@@ -36,9 +36,13 @@ public class AnswerService extends DomainService<Answer> {
      *
      * @param questionId the ID of the question to retrieve answers for
      * @return a list of Answer entities with the specified question ID
+     * @throws EntityNotFoundException if question with questionId does not exist
      */
     @Transactional(readOnly = true)
-    public List<Answer> findAllByQuestionId(String questionId) {
+    public List<Answer> findAllByQuestionId(long questionId) {
+        if (!getRepository().existsById(questionId)) {
+            throw new EntityNotFoundException("Question with id " + questionId + " not found.");
+        }
         return repository.findByQuestionId(questionId);
     }
 
@@ -50,7 +54,7 @@ public class AnswerService extends DomainService<Answer> {
      * @throws EntityNotFoundException if no Answer entity exists with the specified id
      */
     @Transactional(readOnly = true)
-    public Answer find(String id) {
+    public Answer find(long id) {
         return repository.findById(id)
                 .orElseThrow(() -> new EntityNotFoundException("Answer '" + id + "' not found."));
     }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainMapper.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainMapper.java
index 91151e34a7604b75d8ec6e7ef3a4767bbfff811a..39bf0015e1cacc60a34a78e804a77ce18ccc6875 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainMapper.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainMapper.java
@@ -1,10 +1,8 @@
 package org.fuseri.moduleexercise.common;
 
 import org.fuseri.model.dto.common.DomainObjectDto;
-import org.fuseri.model.dto.common.Result;
-import org.mapstruct.Mapping;
-import org.mapstruct.Mappings;
 import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
 
 import java.util.List;
 
@@ -42,18 +40,13 @@ public interface DomainMapper<T extends DomainObject, S extends DomainObjectDto>
     List<S> toDtoList(List<T> entities);
 
     /**
-     * Convert a {@link org.springframework.data.domain.Page} containing entities to a
-     * {@link Result} object containing a list of their corresponding DTO objects, along with
-     * pagination information
+     * Convert a {@link org.springframework.data.domain.Page} containing entities to a page containing DTOs
      *
-     * @param source the Page of entities to be converted
-     * @return a Result object containing a list of DTO objects and pagination information
+     * @param entities entities to be converted to DTOs
+     * @return a Page object containing a list of DTO objects and pagination information
      */
-    @Mappings({
-            @Mapping(target = "total", expression = "java(source.getTotalElements())"),
-            @Mapping(target = "page", expression = "java(source.getNumber())"),
-            @Mapping(target = "pageSize", expression = "java(source.getSize())"),
-            @Mapping(target = "items", expression = "java(toDtoList(source.getContent()))")
-    })
-    Result<S> toResult(Page<T> source);
+    default Page<S> toDtoPage(Page<T> entities) {
+        return new PageImpl<>(toDtoList(entities.getContent()), entities.getPageable(), entities.getTotalPages());
+    }
+
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainObject.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainObject.java
index 077a8e5cdb521f4c233572accf0e6a8bb10ac4d3..aae4e7759835653b19afad27db311e8d23095515 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainObject.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainObject.java
@@ -1,12 +1,12 @@
 package org.fuseri.moduleexercise.common;
 
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
 import jakarta.persistence.MappedSuperclass;
 import lombok.Getter;
 import lombok.Setter;
 
-import java.util.UUID;
-
 /**
  * Represent the base class for entities in the module.
  */
@@ -16,6 +16,7 @@ import java.util.UUID;
 public abstract class DomainObject {
 
     @Id
-    private String id = UUID.randomUUID().toString();
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
 }
 
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainRepository.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainRepository.java
deleted file mode 100644
index fae42adfae3eabea93352b01a26b25d36418bee1..0000000000000000000000000000000000000000
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainRepository.java
+++ /dev/null
@@ -1,57 +0,0 @@
-package org.fuseri.moduleexercise.common;
-
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageRequest;
-
-import java.util.Optional;
-
-/**
- * Dummy interface of repository. Later will be replaced by JpaRepository.
- *
- * @param <T>  entity
- * @param <ID> entity ID
- */
-public interface DomainRepository<T, ID> {
-
-    /**
-     * Save the specified entity
-     *
-     * @param entity entity to be saved
-     * @return created entity
-     */
-    T save(T entity);
-
-    /**
-     * Find entity by ID
-     *
-     * @param id ID of entity to be found
-     * @return {@code Optional} containing the found entity,
-     * or an empty {@code Optional} if no such entity exists
-     */
-    Optional<T> findById(ID id);
-
-    /**
-     * Retrieve a page of entities according to the specified pagination information
-     *
-     * @param pageRequest the pagination information for the query
-     * @return a page of entities that satisfy the pagination criteria
-     */
-    Page<T> findAll(PageRequest pageRequest);
-
-    /**
-     * Update entity
-     *
-     * @param entity entity to update
-     * @return updated entity
-     */
-    T update(T entity);
-
-    /**
-     * Delete the entity with the specified id
-     * Note that this does not do cascade deleting.
-     * We will have cascade deleting with usage of JpaRepository
-     *
-     * @param id the id of the entity to be deleted
-     */
-    void deleteById(ID id);
-}
\ No newline at end of file
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainRepositoryImpl.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainRepositoryImpl.java
deleted file mode 100644
index 5c6b588fa6f6396062c93acc959d2d823284c129..0000000000000000000000000000000000000000
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainRepositoryImpl.java
+++ /dev/null
@@ -1,106 +0,0 @@
-package org.fuseri.moduleexercise.common;
-
-import jakarta.persistence.EntityNotFoundException;
-import lombok.Getter;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageImpl;
-import org.springframework.data.domain.PageRequest;
-
-import java.util.HashSet;
-import java.util.List;
-import java.util.Optional;
-import java.util.Set;
-
-/**
- * Dummy implementation of repository. Later will be replaced by JpaRepository.
- *
- * @param <T>  entity
- */
-public abstract class DomainRepositoryImpl<T extends DomainObject> implements DomainRepository<T, String> {
-
-    /**
-     * Dummy database
-     */
-    @Getter
-    private final Set<T> items = new HashSet<>();
-
-    /**
-     * Save the specified entity
-     *
-     * @param entity entity to be saved
-     * @return created entity
-     */
-    @Override
-    public T save(T entity) {
-        items.add(entity);
-        return entity;
-    }
-
-    /**
-     * Find entity by ID
-     *
-     * @param id ID of entity to be found
-     * @return {@code Optional} containing the found entity,
-     * or an empty {@code Optional} if no such entity exists
-     */
-    @Override
-    public Optional<T> findById(String id) {
-        return items.stream()
-                .filter(e -> e.getId().equals(id))
-                .findFirst();
-    }
-
-    /**
-     * Retrieve a page of entities according to the specified pagination information
-     *
-     * @param pageRequest the pagination information for the query
-     * @return a page of entities that satisfy the pagination criteria
-     */
-    @Override
-    public Page<T> findAll(PageRequest pageRequest) {
-
-        int startIndex = pageRequest.getPageNumber() * pageRequest.getPageSize();
-
-        List<T> pageEntities = items.stream()
-                .skip(startIndex)
-                .limit(pageRequest.getPageSize())
-                .toList();
-
-        return new PageImpl<>(pageEntities, pageRequest, pageEntities.size());
-    }
-
-    /**
-     * Update entity
-     *
-     * @param entity entity to update
-     * @return updated entity
-     */
-    @Override
-    public T update(T entity) {
-        if (entity == null || entity.getId() == null) {
-            throw new IllegalArgumentException("Entity and its ID can not be null.");
-        }
-
-        var optionalEntity = findById(entity.getId());
-        if (optionalEntity.isEmpty()) {
-            throw new EntityNotFoundException("Entity not found with ID: " + entity.getId());
-        }
-
-        T oldEntity = optionalEntity.get();
-        items.remove(oldEntity);
-        items.add(entity);
-        return entity;
-    }
-
-    /**
-     * Delete the entity with the specified id
-     * Note that this does not do cascade deleting.
-     * We will have cascade deleting with usage of JpaRepository
-     *
-     * @param id the id of the entity to be deleted
-     */
-    @Override
-    public void deleteById(String id) {
-        items.removeIf(e -> e.getId().equals(id));
-    }
-}
\ No newline at end of file
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainService.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainService.java
index badd21263def20ee0cf660c2be3f1f156a84aed4..e0824dae22c74ed937ed4a1cbda4dda48a16b912 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainService.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainService.java
@@ -1,5 +1,8 @@
 package org.fuseri.moduleexercise.common;
 
+import jakarta.persistence.EntityNotFoundException;
+import org.springframework.data.jpa.repository.JpaRepository;
+
 /**
  * Represent common service for managing entities
  *
@@ -17,7 +20,7 @@ public abstract class DomainService<T extends DomainObject> {
      *
      * @return the repository used by this service
      */
-    public abstract DomainRepository<T, String> getRepository();
+    public abstract JpaRepository<T, Long> getRepository();
 
     /**
      * Create an entity by saving it to the repository
@@ -32,18 +35,24 @@ public abstract class DomainService<T extends DomainObject> {
     /**
      * Update an entity
      *
+     * @param id the entity ID
      * @param entity the entity to update
      * @return the updated entity
      */
-    public T update(T entity) {
-        return getRepository().update(entity);
+    public T update(long id, T entity) {
+        if (!getRepository().existsById(id)) {
+            throw new EntityNotFoundException("Entity with id " + entity.getId() + " not found.");
+        }
+        entity.setId(id);
+        return getRepository().save(entity);
     }
 
     /**
      * Delete an entity with specified id
      * @param id id of the entity to delete
      */
-    public void delete(String id) {
+    public void delete(long id) {
         getRepository().deleteById(id);
     }
+
 }
\ No newline at end of file
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/Exercise.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/Exercise.java
index 65ff0e59f9a31773168eaf378000bac45f010fd0..6070b8a70b26a36f3e87b4f4661a43a64625cfe5 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/Exercise.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/Exercise.java
@@ -1,5 +1,6 @@
 package org.fuseri.moduleexercise.exercise;
 
+import jakarta.persistence.*;
 import lombok.Builder;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
@@ -18,6 +19,8 @@ import java.util.Set;
 @Setter
 @NoArgsConstructor
 @Builder
+@Entity
+@Table(name = "exercise")
 public class Exercise extends DomainObject {
 
     private String name;
@@ -26,8 +29,10 @@ public class Exercise extends DomainObject {
 
     private int difficulty;
 
-    private String courseId;
+    @Column(name = "lecture_id")
+    private long courseId;
 
+    @OneToMany(mappedBy="exercise", cascade = CascadeType.ALL)
     private Set<Question> questions = new HashSet<>();
 
     /**
@@ -39,7 +44,7 @@ public class Exercise extends DomainObject {
      * @param courseId    id of lecture to which exercise belongs
      * @param questions   question exercise contains
      */
-    public Exercise(String name, String description, int difficulty, String courseId, Set<Question> questions) {
+    public Exercise(String name, String description, int difficulty, long courseId, Set<Question> questions) {
         this.name = name;
         this.description = description;
         this.difficulty = difficulty;
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseController.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseController.java
index 1a53e6f9630c53ba29d16275f982202628181fbf..96f91fc77b92040b231cc51218ff393a26184530 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseController.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseController.java
@@ -1,17 +1,28 @@
 package org.fuseri.moduleexercise.exercise;
 
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import jakarta.persistence.EntityNotFoundException;
 import jakarta.validation.Valid;
-import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
 import jakarta.validation.constraints.PositiveOrZero;
-import org.fuseri.model.dto.common.Result;
 import org.fuseri.model.dto.exercise.ExerciseCreateDto;
 import org.fuseri.model.dto.exercise.ExerciseDto;
+import org.fuseri.model.dto.exercise.QuestionDto;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
 import org.springframework.http.HttpStatus;
-import org.springframework.web.bind.annotation.*;
-import org.springframework.web.server.ResponseStatusException;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
 
 /**
  * Represent a REST API controller for exercises
@@ -21,104 +32,153 @@ import org.springframework.web.server.ResponseStatusException;
 @RequestMapping("/exercises")
 public class ExerciseController {
 
-    private final ExerciseService service;
-
-    private final ExerciseMapper mapper;
+    private final ExerciseFacade facade;
 
     /**
-     * Constructor for AnswerController
+     * Constructor for ExerciseController
      *
-     * @param service the service responsible for handling exercise-related logic
-     * @param mapper  the mapper responsible for converting between DTOs and entities
+     * @param facade the facade responsible for handling exercise-related logic
      */
     @Autowired
-    public ExerciseController(ExerciseService service, ExerciseMapper mapper) {
-        this.service = service;
-        this.mapper = mapper;
+    public ExerciseController(ExerciseFacade facade) {
+        this.facade = facade;
     }
 
     /**
-     * Create a new answer for the given question ID
+     * Create a new exercise
      *
-     * @param dto the ExerciseCreateDto object containing information about the exercise to create
-     * @return an ExerciseDto object representing the newly created exercise
+     * @param dto containing information about the exercise to create
+     * @return a ResponseEntity containing an ExerciseDto object representing the newly created exercise
      */
+    @Operation(summary = "Create an exercise", description = "Creates a new exercise.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "201", description = "Exercise created successfully."),
+            @ApiResponse(responseCode = "400", description = "Invalid input.")
+    })
     @PostMapping
-    public ExerciseDto create(@Valid @RequestBody ExerciseCreateDto dto) {
-        Exercise exercise = mapper.fromCreateDto(dto);
-        return mapper.toDto(service.create(exercise));
+    public ResponseEntity<ExerciseDto> create(@Valid @RequestBody ExerciseCreateDto dto) {
+        ExerciseDto exerciseDto = facade.create(dto);
+        return ResponseEntity.status(HttpStatus.CREATED).body(exerciseDto);
     }
 
     /**
      * Find an exercise by ID
      *
      * @param id the ID of the exercise to find
-     * @return an ExerciseDto object representing the found exercise
+     * @return a ResponseEntity containing an ExerciseDto object representing the found exercise, or a 404 Not Found response
+     * if the exercise with the specified ID was not found
      */
+    @Operation(summary = "Get an exercise by ID", description = "Returns an exercise with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Exercise with the specified ID retrieved successfully."),
+            @ApiResponse(responseCode = "404", description = "Exercise with the specified ID was not found.")
+    })
     @GetMapping("/{id}")
-    public ExerciseDto find(@NotBlank @PathVariable String id) {
-        return mapper.toDto(service.find(id));
+    public ResponseEntity<ExerciseDto> find(@NotNull @PathVariable long id) {
+        try {
+            return ResponseEntity.ok(facade.find(id));
+        } catch (EntityNotFoundException e) {
+            return ResponseEntity.notFound().build();
+        }
     }
 
     /**
-     * Find exercises and return them in a paginated format
+     * Find exercises and return them in paginated format
      *
      * @param page the page number of the exercises to retrieve
-     * @return a Result object containing a list of ExerciseDto objects and pagination information
+     * @return A ResponseEntity containing paginated ExerciseDTOs.
      */
+    @Operation(summary = "Get exercises in paginated format", description = "Returns exercises in paginated format.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Successfully retrieved paginated exercises"),
+            @ApiResponse(responseCode = "400", description = "Invalid page number supplied"),
+    })
     @GetMapping
-    public Result<ExerciseDto> findAll(@PositiveOrZero @RequestParam int page) {
-        Page<Exercise> exercise = service.findAll(page);
-        return mapper.toResult(exercise);
+    public ResponseEntity<Page<ExerciseDto>> findAll(@PositiveOrZero @RequestParam int page) {
+        return ResponseEntity.ok(facade.findAll(page));
     }
 
     /**
      * Find exercises that mach filters and return them in paginated format
      *
-     * @param page       the page number of the exercises to retrieve
      * @param courseId   the id of the course to filter by
      * @param difficulty the difficulty level to filter by
-     * @return a Result object containing a list of filtered ExerciseDto objects woth pagination information
+     * @param page       the page number of the exercises to retrieve
+     * @return A ResponseEntity containing filtered and paginated ExerciseDTOs
      */
+    @Operation(summary = "Filter exercises per difficulty and per course", description = "Returns exercises which belong to specified course and have specified difficulty.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Successfully retrieved filtered paginated exercises."),
+    })
     @GetMapping("filter")
-    public Result<ExerciseDto> findPerDifficultyPerCourse(
-            @PositiveOrZero @RequestParam int page, @NotBlank @RequestParam String courseId,
+    public ResponseEntity<Page<ExerciseDto>> findPerDifficultyPerCourse(
+            @PositiveOrZero @RequestParam int page, @NotNull @RequestParam long courseId,
             @PositiveOrZero @RequestParam int difficulty) {
-        Page<Exercise> exercise = service.findPerDifficultyPerCourse(page, courseId, difficulty);
-        return mapper.toResult(exercise);
+        Page<ExerciseDto> exercises = facade.findByCourseIdAndDifficulty(courseId, difficulty, page);
+        return ResponseEntity.ok(exercises);
+    }
+
+    /**
+     * Find questions by exercise ID and return them in a paginated format
+     *
+     * @param exerciseId the ID of the exercise to find questions for
+     * @param page       the page number of the questions to retrieve
+     * @return a ResponseEntity containing paginated QuestionDTOs which belong to an exercise with exerciseId
+     * or a NOT_FOUND response if the exercise ID is invalid
+     */
+    @Operation(summary = "Find questions belonging to exercise by exercise ID",
+            description = "Returns a paginated list of questions for the specified exercise ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Questions found and returned successfully."),
+            @ApiResponse(responseCode = "404", description = "Exercise with the specified ID was not found.")
+    })
+    @GetMapping("/{exercise-id}/questions")
+    public ResponseEntity<Page<QuestionDto>> findQuestions(@NotNull @PathVariable("exercise-id") long exerciseId,
+                                                           @PositiveOrZero @RequestParam int page) {
+        try {
+            Page<QuestionDto> questions = facade.getQuestions(exerciseId, page);
+            return ResponseEntity.ok(questions);
+        } catch (EntityNotFoundException e) {
+            return ResponseEntity.notFound().build();
+        }
     }
 
     /**
-     * Update an exercise with id
+     * Update an exercise with ID
      *
      * @param id  the ID of the exercise to update
      * @param dto the ExerciseCreateDto object containing information about the exercise to update
-     * @return an ExerciseDto object representing the updated exercise
-     * @throws ResponseStatusException invalid exercise id
+     * @return A ResponseEntity with an ExerciseDto object representing the updated exercise an HTTP status code of 200 if the update was successful.
+     * or a NOT_FOUND response if the exercise ID is invalid
      */
-
+    @Operation(summary = "Update a exercise", description = "Updates a exercise with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Exercise with the specified ID updated successfully."),
+            @ApiResponse(responseCode = "400", description = "Invalid input."),
+            @ApiResponse(responseCode = "404", description = "Exercise with the specified ID was not found.")
+    })
     @PutMapping("/{id}")
-    public ExerciseDto update(@NotBlank @PathVariable String id, @Valid @RequestBody ExerciseCreateDto dto) {
-        Exercise exercise = mapper.fromCreateDto(dto);
-        exercise.setId(id);
-
+    public ResponseEntity<ExerciseDto> update(@NotNull @PathVariable long id, @Valid @RequestBody ExerciseCreateDto dto) {
         try {
-            return mapper.toDto(service.update(exercise));
-        } catch (IllegalArgumentException e) {
-            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, e.getMessage());
+            return ResponseEntity.ok(facade.update(id, dto));
         } catch (EntityNotFoundException e) {
-            throw new ResponseStatusException(HttpStatus.NOT_FOUND, e.getMessage());
+            return ResponseEntity.notFound().build();
         }
     }
 
     /**
-     * Delete an exercise with exerciseId
+     * Delete an exercise with ID
      *
      * @param id the ID of the exercise to delete
      */
+    @Operation(summary = "Delete a exercise with specified ID", description = "Deletes a exercise with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "204", description = "Exercise with the specified ID deleted successfully."),
+    })
     @DeleteMapping("/{id}")
-    public void delete(@NotBlank @PathVariable String id) {
-        service.delete(id);
+    public ResponseEntity<Void> delete(@NotNull @PathVariable long id) {
+        facade.delete(id);
+        return ResponseEntity.noContent().build();
     }
 
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseFacade.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseFacade.java
new file mode 100644
index 0000000000000000000000000000000000000000..3134fadf5997e659f224d894f775c1df19e1ec90
--- /dev/null
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseFacade.java
@@ -0,0 +1,121 @@
+package org.fuseri.moduleexercise.exercise;
+
+import jakarta.persistence.EntityNotFoundException;
+import jakarta.transaction.Transactional;
+import org.fuseri.model.dto.exercise.ExerciseCreateDto;
+import org.fuseri.model.dto.exercise.ExerciseDto;
+import org.fuseri.model.dto.exercise.QuestionDto;
+import org.fuseri.moduleexercise.question.Question;
+import org.fuseri.moduleexercise.question.QuestionMapper;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
+import org.springframework.stereotype.Service;
+
+/**
+ * Represent facade for managing exercises
+ * Provide simplified interface for manipulating with exercises
+ */
+@Service
+@Transactional
+public class ExerciseFacade {
+    private final ExerciseService exerciseService;
+    private final ExerciseMapper exerciseMapper;
+    private final QuestionMapper questionMapper;
+
+    /**
+     * Constructor for AnswerFacade
+     *
+     * @param exerciseService the service responsible for handling answer-related logic
+     * @param exerciseMapper  the mapper responsible for converting between DTOs and entities
+     */
+    @Autowired
+    public ExerciseFacade(ExerciseService exerciseService, ExerciseMapper exerciseMapper, QuestionMapper questionMapper) {
+        this.exerciseService = exerciseService;
+        this.exerciseMapper = exerciseMapper;
+        this.questionMapper = questionMapper;
+    }
+
+    /**
+     * Create a new exercise
+     *
+     * @param exerciseDto dto with information from which exercise is created
+     * @return a created exercise dto
+     */
+    public ExerciseDto create(ExerciseCreateDto exerciseDto) {
+        Exercise exerciseToCreate = exerciseMapper.fromCreateDto(exerciseDto);
+        Exercise createdExercise = exerciseService.create(exerciseToCreate);
+        return exerciseMapper.toDto(createdExercise);
+    }
+
+    /**
+     * Retrieve the Exercise entity with the specified ID
+     *
+     * @param id the ID of the Exercise entity to retrieve
+     * @return the Exercise entity with the specified ID
+     * @throws EntityNotFoundException if no Exercise entity exists with the specified ID
+     */
+    @org.springframework.transaction.annotation.Transactional(readOnly = true)
+    public ExerciseDto find(long id) {
+        return exerciseMapper.toDto(exerciseService.find(id));
+    }
+
+    /**
+     * Retrieve a page of Exercise entities
+     *
+     * @param page the page number to retrieve (0-indexed)
+     * @return paginated exerciseDTOs
+     */
+    @org.springframework.transaction.annotation.Transactional(readOnly = true)
+    public Page<ExerciseDto> findAll(int page) {
+        return exerciseMapper.toDtoPage(exerciseService.findAll(page));
+    }
+
+    /**
+     * Retrieve a page of exercises filtered by the specified course id and difficulty level
+     *
+     * @param page       the page number to retrieve
+     * @param courseId   the id of the course to filter by
+     * @param difficulty the difficulty level to filter by
+     * @return paginated exerciseDTOs filtered by the specified course ID and difficulty level
+     */
+    public Page<ExerciseDto> findByCourseIdAndDifficulty(long courseId, int difficulty, int page) {
+        Page<Exercise> exercises = exerciseService.findByCourseIdAndDifficulty(courseId, difficulty, page);
+        return exerciseMapper.toDtoPage(exercises);
+    }
+
+    /**
+     * Retrieve a page of Question entities associated with the specified exercise ID
+     *
+     * @param exerciseId the ID of the exercise to retrieve questions for
+     * @param page       the page number to retrieve (0-indexed)
+     * @return paginated questionDTOs associated with the specified exercise ID
+     */
+    @org.springframework.transaction.annotation.Transactional(readOnly = true)
+    public Page<QuestionDto> getQuestions(long exerciseId, int page) {
+        Page<Question> questions = exerciseService.getQuestions(exerciseId, page);
+        return questionMapper.toDtoPage(questions);
+    }
+
+    /**
+     * Update exercise
+     *
+     * @param id  the ID of the exercise to update
+     * @param dto the ExerciseCreateDto object containing information about the exercise to update
+     * @return an ExerciseDto object representing the updated exercise
+     */
+    public ExerciseDto update(long id, ExerciseCreateDto dto) {
+        Exercise exercise = exerciseMapper.fromCreateDto(dto);
+        Exercise updatedExercise = exerciseService.update(id, exercise);
+        return exerciseMapper.toDto(updatedExercise);
+    }
+
+    /**
+     * Delete exercise
+     *
+     * @param id of exercise to delete
+     */
+    public void delete(long id) {
+        exerciseService.delete(id);
+    }
+
+}
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseMapper.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseMapper.java
index 3c211aaa5d034ecba3b54e738da0ebb4315b51bf..3b44db86873b1f10c1911149a9a018f25dfb423a 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseMapper.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseMapper.java
@@ -1,9 +1,14 @@
 package org.fuseri.moduleexercise.exercise;
 
+import org.fuseri.model.dto.course.CourseDto;
 import org.fuseri.model.dto.exercise.ExerciseCreateDto;
 import org.fuseri.model.dto.exercise.ExerciseDto;
 import org.fuseri.moduleexercise.common.DomainMapper;
 import org.mapstruct.Mapper;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+
+import java.util.List;
 
 /**
  * Mapper between Exercises and their corresponding DTOs
@@ -18,4 +23,10 @@ public interface ExerciseMapper extends DomainMapper<Exercise, ExerciseDto> {
      * @return corresponding Exercise entity created from DTO
      */
     Exercise fromCreateDto(ExerciseCreateDto dto);
+
+    List<ExerciseDto> mapToList(List<Exercise> persons);
+
+    default Page<ExerciseDto> mapToPageDto(Page<Exercise> courses) {
+        return new PageImpl<>(mapToList(courses.getContent()), courses.getPageable(), courses.getTotalPages());
+    }
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepository.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepository.java
index 76ec2a3a1eaf05eb979ccd4cdd8d5267397addb3..a2ff556892065d2be6b365566bf3bac9a6e0a504 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepository.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepository.java
@@ -1,24 +1,34 @@
 package org.fuseri.moduleexercise.exercise;
 
-import org.fuseri.model.dto.common.Result;
-import org.fuseri.moduleexercise.common.DomainRepository;
+import org.fuseri.moduleexercise.question.Question;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
 
 /**
  * A repository interface for managing Exercise entities
  */
-public interface ExerciseRepository extends DomainRepository<Exercise, String> {
+@Repository
+public interface ExerciseRepository extends JpaRepository<Exercise, Long> {
 
     /**
      * Filters the exercises by the specified difficulty level and course id,
-     * and returns a {@link Result} object containing these filtered exercises
+     * and returns an object containing these filtered exercises
      * along with pagination information
      *
-     * @param pageRequest the pagination settings for the result
-     * @param courseId    the id of the course to filter by
-     * @param difficulty  the difficulty level to filter by
-     * @return a {@link Result} object containing a list of paginated exercises that match the filter criteria
+     * @param courseId   the id of the course to filter by
+     * @param difficulty the difficulty level to filter by
+     * @param pageable   the pagination settings
+     * @return object containing a list of paginated exercises that match the filter criteria
      */
-    Page<Exercise> filterPerDifficultyPerCourse(PageRequest pageRequest, String courseId, int difficulty);
+    @Query("SELECT e FROM Exercise e WHERE e.courseId = :courseId AND e.difficulty = :difficulty")
+    Page<Exercise> findByCourseIdAndDifficulty(long courseId, int difficulty, Pageable pageable);
+
+    @Query("SELECT q FROM Exercise e JOIN e.questions q WHERE e.id = :exerciseId")
+    Page<Question> getQuestions(PageRequest pageRequest, @Param("exerciseId") Long exerciseId);
+
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepositoryImpl.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepositoryImpl.java
deleted file mode 100644
index 3036f93b02043658d38c332c45d2cbc154f308c6..0000000000000000000000000000000000000000
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepositoryImpl.java
+++ /dev/null
@@ -1,42 +0,0 @@
-package org.fuseri.moduleexercise.exercise;
-
-import org.fuseri.model.dto.common.Result;
-import org.fuseri.moduleexercise.common.DomainRepositoryImpl;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageImpl;
-import org.springframework.data.domain.PageRequest;
-import org.springframework.stereotype.Repository;
-
-import java.util.List;
-
-/**
- * An implementation of the ExerciseRepository interface
- * Provides access to Exercise entities stored in a data source
- */
-@Repository
-public class ExerciseRepositoryImpl extends DomainRepositoryImpl<Exercise> implements ExerciseRepository {
-
-    /**
-     * Filters the exercises by the specified difficulty level and course id,
-     * and returns a {@link Result} object containing these filtered exercises
-     * along with pagination information
-     *
-     * @param pageRequest the pagination settings for the result
-     * @param courseId    the id of the course to filter by
-     * @param difficulty  the difficulty level to filter by
-     * @return a {@link Result} object containing a list of paginated exercises that match the filter criteria
-     */
-    @Override
-    public Page<Exercise> filterPerDifficultyPerCourse(PageRequest pageRequest, String courseId, int difficulty) {
-
-        int startIndex = pageRequest.getPageNumber() * pageRequest.getPageSize();
-
-        List<Exercise> pageEntities = getItems().stream()
-                .filter(e -> e.getCourseId().equals(courseId) && e.getDifficulty() == difficulty)
-                .skip(startIndex)
-                .limit(pageRequest.getPageSize())
-                .toList();
-
-        return new PageImpl<>(pageEntities, pageRequest, pageEntities.size());
-    }
-}
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseService.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseService.java
index 677c704a7892b13672c8534c0d731d3ba7a2abb6..41aa3c7e68a9c05b82fe0634d17c481525451d7c 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseService.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseService.java
@@ -3,6 +3,7 @@ package org.fuseri.moduleexercise.exercise;
 import jakarta.persistence.EntityNotFoundException;
 import lombok.Getter;
 import org.fuseri.moduleexercise.common.DomainService;
+import org.fuseri.moduleexercise.question.Question;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
@@ -39,7 +40,7 @@ public class ExerciseService extends DomainService<Exercise> {
      * @throws EntityNotFoundException if no Exercise entity exists with the specified ID
      */
     @Transactional(readOnly = true)
-    public Exercise find(String id) {
+    public Exercise find(long id) {
         return repository.findById(id)
                 .orElseThrow(() -> new EntityNotFoundException("Exercise '" + id + "' not found."));
     }
@@ -58,13 +59,30 @@ public class ExerciseService extends DomainService<Exercise> {
     /**
      * Retrieve a page of exercises filtered by the specified course id and difficulty level
      *
-     * @param page       the page number to retrieve
      * @param courseId   the id of the course to filter by
      * @param difficulty the difficulty level to filter by
-     * @return a {@link Page} of {@link Exercise} objects filtered by the specified course id and difficulty level
+     * @param page       the page number to retrieve
+     * @return paginated exercises filtered by the specified course ID and difficulty level
      */
-    public Page<Exercise> findPerDifficultyPerCourse(int page, String courseId, int difficulty) {
-        return repository.filterPerDifficultyPerCourse(
-                PageRequest.of(page, DEFAULT_PAGE_SIZE), courseId, difficulty);
+    public Page<Exercise> findByCourseIdAndDifficulty(long courseId, int difficulty, int page) {
+        return repository.findByCourseIdAndDifficulty(courseId, difficulty, PageRequest.of(page, DEFAULT_PAGE_SIZE));
     }
+
+    /**
+     * Retrieve a page of Question entities associated with the specified exercise ID
+     *
+     * @param exerciseId the ID of the exercise to retrieve questions for
+     * @param page       the page number to retrieve (0-indexed)
+     * @return a page of Question entities associated with the specified exercise ID
+     */
+    @Transactional(readOnly = true)
+    public Page<Question> getQuestions(long exerciseId, int page) {
+        if (!repository.existsById(exerciseId)) {
+            throw new EntityNotFoundException("Exercise with ID " + exerciseId + "does not exist.");
+        }
+        return repository.getQuestions(
+                PageRequest.of(page, DomainService.DEFAULT_PAGE_SIZE),
+                exerciseId);
+    }
+
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/Question.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/Question.java
index 042604af6ad1e339be34b38f5481806938dfbb38..03f62910b63062589484675c9f4d1ba436ec60c5 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/Question.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/Question.java
@@ -1,14 +1,21 @@
 package org.fuseri.moduleexercise.question;
 
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 import org.fuseri.moduleexercise.answer.Answer;
 import org.fuseri.moduleexercise.common.DomainObject;
+import org.fuseri.moduleexercise.exercise.Exercise;
 
 import java.util.HashSet;
-import java.util.Objects;
 import java.util.Set;
 
 /**
@@ -17,25 +24,27 @@ import java.util.Set;
 @Getter
 @Setter
 @NoArgsConstructor
+@AllArgsConstructor
 @Builder
+@Entity
+@Table(name = "question")
 public class Question extends DomainObject {
 
     private String text;
 
+    @OneToMany(mappedBy = "question", cascade = CascadeType.ALL, orphanRemoval = true)
     private Set<Answer> answers = new HashSet<>();
 
-    private String exerciseId;
+    @ManyToOne
+    @JoinColumn(name = "exercise_id", nullable = false)
+    private Exercise exercise;
 
     /**
-     * Constructor of question
+     * Add answers to question
      *
-     * @param text       question text
-     * @param answers    question answers
-     * @param exerciseId id of exercise the question belongs to
+     * @param answersToAdd to add
      */
-    public Question(String text, Set<Answer> answers, String exerciseId) {
-        this.text = text;
-        this.answers = Objects.requireNonNullElseGet(answers, HashSet::new);
-        this.exerciseId = exerciseId;
+    public void addAnswers(Set<Answer> answersToAdd) {
+        answers.addAll(answersToAdd);
     }
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionController.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionController.java
index bd217cc1c00f36d02b1b074b6e9028c20e291220..9857e1c3d46120979b04339b2ddf0293c22c0ed8 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionController.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionController.java
@@ -1,17 +1,32 @@
 package org.fuseri.moduleexercise.question;
 
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import jakarta.persistence.EntityNotFoundException;
 import jakarta.validation.Valid;
-import jakarta.validation.constraints.NotBlank;
-import jakarta.validation.constraints.PositiveOrZero;
-import org.fuseri.model.dto.common.Result;
+import jakarta.validation.constraints.NotNull;
+import org.fuseri.model.dto.exercise.AnswerDto;
+import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
 import org.fuseri.model.dto.exercise.QuestionCreateDto;
 import org.fuseri.model.dto.exercise.QuestionDto;
 import org.fuseri.model.dto.exercise.QuestionUpdateDto;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
-import org.springframework.web.bind.annotation.*;
-import org.springframework.web.server.ResponseStatusException;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PatchMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
 
 /**
  * Represent a REST API controller for questions
@@ -37,40 +52,64 @@ public class QuestionController {
      * Find a question by ID.
      *
      * @param id the ID of the question to find
-     * @return a QuestionDto object representing the found question
+     * @return a ResponseEntity containing a QuestionDto object representing the found question, or a 404 Not Found response
+     * if the question with the specified ID was not found
      */
+    @Operation(summary = "Get a question by ID", description = "Returns a question with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Question with the specified ID retrieved successfully.",
+                    content = @Content(schema = @Schema(implementation = QuestionDto.class))),
+            @ApiResponse(responseCode = "404", description = "Question with the specified ID was not found.")
+    })
     @GetMapping("/{id}")
-    public QuestionDto find(@NotBlank @PathVariable String id) {
-        return questionFacade.find(id);
+    public ResponseEntity<QuestionDto> find(@NotNull @PathVariable long id) {
+        try {
+            return ResponseEntity.ok(questionFacade.find(id));
+        } catch (EntityNotFoundException e) {
+            return ResponseEntity.notFound().build();
+        }
     }
 
     /**
-     * Find questions by exercise ID and return them in a paginated format
+     * Retrieve a list of AnswerDto objects which belong to the question with ID
      *
-     * @param exerciseId the ID of the exercise to find questions for
-     * @param page       the page number of the questions to retrieve
-     * @return a Result object containing a list of QuestionDto objects and pagination information
+     * @param id the ID of the question for which to retrieve answers
+     * @return a ResponseEntity containing a List of AnswerDto objects, or a 404 Not Found response
+     * if the question with the specified ID was not found
      */
-    @GetMapping("/exercise/{exercise-id}")
-    public Result<QuestionDto> findByExerciseId(@NotBlank @PathVariable("exercise-id") String exerciseId,
-                                                @PositiveOrZero @RequestParam int page) {
-        return questionFacade.findByExerciseId(exerciseId, page);
+    @Operation(summary = "Retrieve answers for a specific question")
+    @ApiResponse(responseCode = "200", description = "Successfully retrieved answers",
+            content = @Content(schema = @Schema(implementation = AnswerDto.class)))
+    @ApiResponse(responseCode = "404", description = "Question not found")
+    @GetMapping("/{id}/answers")
+    public ResponseEntity<List<AnswerDto>> getQuestionAnswers(@NotNull @PathVariable long id) {
+        try {
+            return ResponseEntity.ok(questionFacade.getQuestionAnswers(id));
+        } catch (EntityNotFoundException e) {
+            return ResponseEntity.notFound().build();
+        }
     }
 
     /**
      * Add a new question to an exercise
      *
      * @param dto a QuestionCreateDto object representing the new question to add
-     * @return a QuestionDto object representing the added question
-     * @throws ResponseStatusException if the exercise with exerciseId from QuestionCreateDto does not exist
+     * @return a ResponseEntity containing a QuestionDto object representing the posted question, or a 404 Not Found response
+     * if the exercise with the specified ID in dto was not found
      */
+    @Operation(summary = "Add a new question with answers to an exercise", description = "Creates a new question with answers and associates it with the specified exercise.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "201", description = "Question with answers created and added to the exercise successfully.",
+                    content = @Content(schema = @Schema(implementation = QuestionDto.class))),
+            @ApiResponse(responseCode = "404", description = "Exercise with the specified ID was not found.")
+    })
     @PostMapping
-    public QuestionDto addQuestion(@Valid @RequestBody QuestionCreateDto dto) {
+    public ResponseEntity<QuestionDto> addQuestion(@Valid @RequestBody QuestionCreateDto dto) {
         try {
-            return questionFacade.create(dto);
+            QuestionDto createdQuestionDto = questionFacade.create(dto);
+            return ResponseEntity.status(HttpStatus.CREATED).body(createdQuestionDto);
         } catch (EntityNotFoundException e) {
-            throw new ResponseStatusException(HttpStatus.NOT_FOUND,
-                    e.getMessage());
+            return ResponseEntity.notFound().build();
         }
     }
 
@@ -78,27 +117,52 @@ public class QuestionController {
      * Update question
      *
      * @param dto a QuestionDto object representing the updated question with correct id
-     * @return a QuestionUpdateDto object representing the updated question
-     * @throws ResponseStatusException if the question with id doesn't exist or its exercise doesn't exist
+     * @return a ResponseEntity containing a QuestionUpdateDto object representing the updated question,
+     * or a 404 Not Found response if the question with the specified ID was not found
      */
+    @Operation(summary = "Update a question by ID", description = "Updates a question with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Question with the specified ID updated successfully."),
+            @ApiResponse(responseCode = "404", description = "Question with the specified ID was not found.")
+    })
     @PutMapping("/{id}")
-    public QuestionDto updateQuestion(@NotBlank @PathVariable String id, @Valid @RequestBody QuestionUpdateDto dto) {
+    public ResponseEntity<QuestionDto> updateQuestion(@NotNull @PathVariable long id, @Valid @RequestBody QuestionUpdateDto dto) {
         try {
-            return questionFacade.update(id, dto);
-        } catch (IllegalArgumentException e) {
-            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, e.getMessage());
+            return ResponseEntity.ok(questionFacade.patchUpdate(id, dto));
         } catch (EntityNotFoundException e) {
-            throw new ResponseStatusException(HttpStatus.NOT_FOUND, e.getMessage());
+            return ResponseEntity.notFound().build();
         }
     }
 
     /**
-     * Add a new question to an exercise
+     * Delete question with ID from exercise
      *
      * @param id of question to delete
      */
+    @Operation(summary = "Delete a question with specified ID", description = "Deletes a question with the specified ID.")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "204", description = "Question with the specified ID deleted successfully."),
+    })
     @DeleteMapping("/{id}")
-    public void deleteQuestion(@NotBlank @PathVariable String id) {
+    public ResponseEntity<Void> deleteQuestion(@NotNull @PathVariable long id) {
         questionFacade.delete(id);
+        return ResponseEntity.noContent().build();
+    }
+
+    /**
+     * Adds answers to the existing question resource
+     *
+     * @param id id of question to update
+     * @return the LectureDto representing the updated lecture
+     */
+    @Operation(summary = "Add answers to the existing question.")
+    @PatchMapping("/{id}/answers")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "The question has been successfully updated"),
+            @ApiResponse(responseCode = "400", description = "The request body is invalid"),
+            @ApiResponse(responseCode = "404", description = "The question with the specified ID does not exist")
+    })
+    public ResponseEntity<QuestionDto> addAnswers(@PathVariable Long id, @RequestBody List<AnswerInQuestionCreateDto> answerDtoList) {
+        return ResponseEntity.ok(questionFacade.addAnswers(id, answerDtoList));
     }
 }
\ No newline at end of file
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionFacade.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionFacade.java
index 2f2cfc9f4219b69c9c475ecc70c6c4de428233a5..8fe1e2a19f4fd2663aa3a22e0e5f9848829f8800 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionFacade.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionFacade.java
@@ -1,40 +1,36 @@
 package org.fuseri.moduleexercise.question;
 
-import org.fuseri.model.dto.common.Result;
+import jakarta.transaction.Transactional;
+import org.fuseri.model.dto.exercise.AnswerDto;
+import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
 import org.fuseri.model.dto.exercise.QuestionCreateDto;
 import org.fuseri.model.dto.exercise.QuestionDto;
 import org.fuseri.model.dto.exercise.QuestionUpdateDto;
-import org.fuseri.moduleexercise.answer.Answer;
 import org.fuseri.moduleexercise.answer.AnswerMapper;
 import org.fuseri.moduleexercise.answer.AnswerService;
-import org.fuseri.moduleexercise.exercise.Exercise;
-import org.fuseri.moduleexercise.exercise.ExerciseService;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.data.domain.Page;
 import org.springframework.stereotype.Service;
 
-import java.util.HashSet;
 import java.util.List;
 
 /**
  * Represent facade for managing questions
  * Provide simplified interface for manipulating with questions
  */
+@Transactional
 @Service
 public class QuestionFacade {
     private final QuestionService questionService;
-    private final ExerciseService exerciseService;
     private final AnswerService answerService;
     private final QuestionMapper questionMapper;
     private final AnswerMapper answerMapper;
 
     @Autowired
     public QuestionFacade(
-            QuestionService questionService, ExerciseService exerciseService,
+            QuestionService questionService,
             AnswerService answerService, QuestionMapper questionMapper,
             AnswerMapper answerMapper) {
         this.questionService = questionService;
-        this.exerciseService = exerciseService;
         this.answerService = answerService;
         this.questionMapper = questionMapper;
         this.answerMapper = answerMapper;
@@ -46,21 +42,29 @@ public class QuestionFacade {
      * @param id the ID of the question to find
      * @return a QuestionDto object representing the found question
      */
-    public QuestionDto find(String id) {
-        var a = questionService.find(id);
-        return questionMapper.toDto(a);
+    public QuestionDto find(long id) {
+        return questionMapper.toDto(questionService.find(id));
     }
 
     /**
-     * Find questions by exercise ID and return them in a paginated format
+     * Retrieve a list of AnswerDto objects which belong to question with questionId
      *
-     * @param exerciseId the ID of the exercise to find questions for
-     * @param page       the page number of the questions to retrieve
-     * @return a Result object containing a list of QuestionDto objects and pagination information
+     * @param questionId the ID of the question for which to retrieve answers
+     * @return a List of AnswerDto objects
      */
-    public Result<QuestionDto> findByExerciseId(String exerciseId, int page) {
-        Page<Question> questions = questionService.findByExerciseId(exerciseId, page);
-        return questionMapper.toResult(questions);
+    public List<AnswerDto> getQuestionAnswers(long questionId) {
+        return answerMapper.toDtoList(answerService.findAllByQuestionId(questionId));
+    }
+
+    /**
+     * Add answers to question
+     *
+     * @param id  question ID
+     * @param dto List with AnswerInQuestionCreateDto to add to question
+     * @return a QuestionDto object representing the updated question
+     */
+    public QuestionDto addAnswers(Long id, List<AnswerInQuestionCreateDto> dto) {
+        return questionMapper.toDto(questionService.addAnswers(id, answerMapper.fromCreateDtoList(dto)));
     }
 
     /**
@@ -70,30 +74,7 @@ public class QuestionFacade {
      * @return a QuestionDto object representing the added question
      */
     public QuestionDto create(QuestionCreateDto dto) {
-        Question question = questionMapper.fromCreateDto(dto);
-
-        Exercise exercise;
-        exercise = exerciseService.find(question.getExerciseId());
-
-        exercise.getQuestions().add(question);
-        question.setExerciseId(exercise.getId());
-
-        var answerDtos = dto.getAnswers();
-        var answers = new HashSet<Answer>();
-        for (var answerDto : answerDtos) {
-            Answer answer = answerMapper.fromCreateDto(answerDto);
-            answer = answerService.create(answer);
-            answers.add(answer);
-        }
-
-        question.setAnswers(answers);
-        var createdQuestion = questionService.create(question);
-
-        for (var answer : answers) {
-            answer.setQuestionId(createdQuestion.getId());
-        }
-
-        return questionMapper.toDto(createdQuestion);
+        return questionMapper.toDto(questionService.create(questionMapper.fromCreateDto(dto)));
     }
 
     /**
@@ -102,12 +83,8 @@ public class QuestionFacade {
      * @param dto dto of updated question with correct id
      * @return dto of updated question
      */
-    public QuestionDto update(String id, QuestionUpdateDto dto) {
-        Question question = questionMapper.fromUpdateDto(dto);
-        question.setId(id);
-        List<Answer> questionAnswers = answerService.findAllByQuestionId(id);
-        question.setAnswers(new HashSet<>(questionAnswers));
-        Question updatedQuestion = questionService.update(question);
+    public QuestionDto patchUpdate(long id, QuestionUpdateDto dto) {
+        var updatedQuestion = questionService.patchUpdateWithoutAnswers(id, questionMapper.fromUpdateDto(dto));
         return questionMapper.toDto(updatedQuestion);
     }
 
@@ -116,11 +93,7 @@ public class QuestionFacade {
      *
      * @param id of qustion to delete
      */
-    public void delete(String id) {
-        var question = questionService.find(id);
-        for (var answer : question.getAnswers()) {
-            answerService.delete(answer.getId());
-        }
+    public void delete(long id) {
         questionService.delete(id);
     }
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionMapper.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionMapper.java
index 9c4e62a2a7845c32941b219a539030fcdbf98a16..b3cd97079670ef1e2c239e08076a8748643b7110 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionMapper.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionMapper.java
@@ -1,17 +1,53 @@
 package org.fuseri.moduleexercise.question;
 
+import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
 import org.fuseri.model.dto.exercise.QuestionCreateDto;
 import org.fuseri.model.dto.exercise.QuestionDto;
 import org.fuseri.model.dto.exercise.QuestionUpdateDto;
+import org.fuseri.moduleexercise.answer.Answer;
+import org.fuseri.moduleexercise.answer.AnswerMapper;
 import org.fuseri.moduleexercise.common.DomainMapper;
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.fuseri.moduleexercise.exercise.ExerciseService;
 import org.mapstruct.Mapper;
 import org.mapstruct.Mapping;
+import org.mapstruct.Named;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.util.List;
+import java.util.Set;
 
 /**
  * Mapper between Questions and their corresponding DTOs
  */
-@Mapper
-public interface QuestionMapper extends DomainMapper<Question, QuestionDto> {
+@Mapper(componentModel = "spring", uses = {AnswerMapper.class, ExerciseService.class})
+public abstract class QuestionMapper implements DomainMapper<Question, QuestionDto> {
+
+    @Autowired
+    private ExerciseService exerciseService;
+
+    @Autowired
+    private AnswerMapper answerMapper;
+
+    @Named("mapIdToExercise")
+    public Exercise mapIdToExercise(Long id) {
+        return exerciseService.find(id);
+    }
+
+    @Named("mapDtoAnswersToAnswers")
+    public Set<Answer> mapDtoAnswersToAnswers(List<AnswerInQuestionCreateDto> dtos) {
+        return answerMapper.fromCreateDtoList(dtos);
+    }
+
+    /**
+     * Convert entity to its corresponding DTO
+     *
+     * @param question to be converted
+     * @return corresponding DTO created from question
+     */
+    @Override
+    @Mapping(target = "exerciseId", source = "question.exercise.id")
+    public abstract QuestionDto toDto(Question question);
 
     /**
      * Convert DTO of type QuestionCreateDto to Question
@@ -19,8 +55,10 @@ public interface QuestionMapper extends DomainMapper<Question, QuestionDto> {
      * @param dto DTO to be converted
      * @return corresponding Question entity created from DTO
      */
-    @Mapping(target = "answers", ignore = true)
-    Question fromCreateDto(QuestionCreateDto dto);
+    @Mapping(target = "exercise", source = "dto.exerciseId", qualifiedByName = "mapIdToExercise")
+    @Mapping(target = "answers", source = "dto.answers", qualifiedByName = "mapDtoAnswersToAnswers")
+    public abstract Question fromCreateDto(QuestionCreateDto dto);
 
-    Question fromUpdateDto(QuestionUpdateDto dto);
+    @Mapping(target = "exercise", source = "dto.exerciseId", qualifiedByName = "mapIdToExercise")
+    public abstract Question fromUpdateDto(QuestionUpdateDto dto);
 }
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepository.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepository.java
index 0f924cd5794fbfb300a826813de050a1dc7b4222..b5b2adc4d3208451e1d1789654def49121feb14f 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepository.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepository.java
@@ -1,20 +1,11 @@
 package org.fuseri.moduleexercise.question;
 
-import org.fuseri.moduleexercise.common.DomainRepository;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageRequest;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
 
 /**
  * A repository interface for managing Question entities
  */
-public interface QuestionRepository extends DomainRepository<Question, String> {
-
-    /**
-     * Find a page of questions associated with the exercise with the specified ID
-     *
-     * @param exerciseId  the ID of the exercise to find questions for
-     * @param pageRequest the page request specifying the page number and page size
-     * @return a page of questions associated with the specified exercise
-     */
-    Page<Question> findByExerciseId(String exerciseId, PageRequest pageRequest);
+@Repository
+public interface QuestionRepository extends JpaRepository<Question, Long> {
 }
\ No newline at end of file
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepositoryImpl.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepositoryImpl.java
deleted file mode 100644
index 703b89dcd133afb330a3468fb0e24cc60d0e41d4..0000000000000000000000000000000000000000
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepositoryImpl.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package org.fuseri.moduleexercise.question;
-
-import org.fuseri.moduleexercise.common.DomainRepositoryImpl;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageImpl;
-import org.springframework.data.domain.PageRequest;
-import org.springframework.stereotype.Repository;
-
-import java.util.List;
-
-/**
- * An implementation of the QuestionRepository interface
- * Provides access to Question entities stored in a data source
- */
-@Repository
-public class QuestionRepositoryImpl extends DomainRepositoryImpl<Question> implements QuestionRepository {
-
-    /**
-     * Find a page of questions associated with the exercise with the specified ID
-     *
-     * @param exerciseId  the ID of the exercise to find questions for
-     * @param pageRequest the page request specifying the page number and page size
-     * @return a page of questions associated with the specified exercise
-     */
-    @Override
-    public Page<Question> findByExerciseId(String exerciseId, PageRequest pageRequest) {
-        List<Question> filteredQuestions = getItems()
-                .stream()
-                .filter(e -> e.getExerciseId().equals(exerciseId))
-                .skip(pageRequest.getOffset())
-                .limit(pageRequest.getPageSize())
-                .toList();
-
-        return new PageImpl<>(filteredQuestions, pageRequest, filteredQuestions.size());
-    }
-}
diff --git a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionService.java b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionService.java
index f30867aa5da680b2f61004a645c8fe1b21534161..f0676eee28256d926e768b0fee5df3cf52275fac 100644
--- a/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionService.java
+++ b/application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionService.java
@@ -2,13 +2,15 @@ package org.fuseri.moduleexercise.question;
 
 import jakarta.persistence.EntityNotFoundException;
 import lombok.Getter;
+import org.fuseri.moduleexercise.answer.Answer;
 import org.fuseri.moduleexercise.common.DomainService;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.data.domain.Page;
-import org.springframework.data.domain.PageRequest;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.util.Optional;
+import java.util.Set;
+
 /**
  * Represent a service for managing Question entities
  */
@@ -39,23 +41,48 @@ public class QuestionService extends DomainService<Question> {
      * @throws EntityNotFoundException if no Question entity exists with the specified ID
      */
     @Transactional(readOnly = true)
-    public Question find(String id) {
+    public Question find(long id) {
         return repository.findById(id)
                 .orElseThrow(() -> new EntityNotFoundException("Question '" + id + "' not found."));
     }
 
     /**
-     * Retrieve a page of Question entities associated with the specified exercise ID
+     * Patch update a question. Don't update question answers.
      *
-     * @param exerciseId the ID of the exercise to retrieve questions for
-     * @param page       the page number to retrieve (0-indexed)
-     * @return a page of Question entities associated with the specified exercise ID
+     * @param id              the question ID
+     * @param updatedQuestion the question to update
+     * @return the updated question
      */
-    @Transactional(readOnly = true)
-    public Page<Question> findByExerciseId(String exerciseId, int page) {
-        return repository.findByExerciseId(
-                exerciseId,
-                PageRequest.of(page, DomainService.DEFAULT_PAGE_SIZE));
+    @Transactional
+    public Question patchUpdateWithoutAnswers(Long id, Question updatedQuestion) {
+        Optional<Question> optionalQuestion = repository.findById(id);
+        if (optionalQuestion.isPresent()) {
+            Question question = optionalQuestion.get();
+            question.setText(updatedQuestion.getText());
+            question.setExercise(updatedQuestion.getExercise());
+            return repository.save(question);
+        } else {
+            throw new EntityNotFoundException("Question with id: " + id + " was not found.");
+        }
     }
 
+    /**
+     * Add answers to question with question ID.
+     *
+     * @param id      of question
+     * @param answers to add to question
+     * @return updated question
+     */
+    public Question addAnswers(Long id, Set<Answer> answers) {
+        Optional<Question> optionalQuestion = repository.findById(id);
+        if (optionalQuestion.isPresent()) {
+            Question question = optionalQuestion.get();
+            question.addAnswers(answers);
+            return repository.save(question);
+        } else {
+            throw new EntityNotFoundException(
+                    "Question with id: " + id + " was not found.");
+        }
+
+    }
 }
diff --git a/application/module-exercise/src/main/resources/application.properties b/application/module-exercise/src/main/resources/application.properties
index ec3c390e0877b6c499b7aade0abc0111d719d865..22a97362c389b6439b4b17bb0c4e7d144ce4f1a5 100644
--- a/application/module-exercise/src/main/resources/application.properties
+++ b/application/module-exercise/src/main/resources/application.properties
@@ -1 +1,3 @@
-server.port=5002
\ No newline at end of file
+server.port=5002
+spring.h2.console.enabled=true
+spring.datasource.url=jdbc:h2:mem:exercices
\ No newline at end of file
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerControllerTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerControllerTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..66eaea5afcd6ba64f557df3e63151398ea0bf233
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerControllerTest.java
@@ -0,0 +1,180 @@
+package org.fuseri.moduleexercise.answer;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import jakarta.persistence.EntityNotFoundException;
+import org.fuseri.model.dto.exercise.AnswerCreateDto;
+import org.fuseri.model.dto.exercise.AnswerDto;
+import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
+import org.fuseri.model.dto.exercise.AnswersCreateDto;
+import org.fuseri.model.dto.exercise.ExerciseCreateDto;
+import org.fuseri.model.dto.exercise.QuestionCreateDto;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentMatchers;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.List;
+
+import static org.hamcrest.Matchers.is;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc
+public class AnswerControllerTest {
+
+    @Autowired
+    ObjectMapper objectMapper;
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockBean
+    private AnswerFacade answerFacade;
+    long exerciseId = 1L;
+    ExerciseCreateDto exercise;
+    QuestionCreateDto question1;
+    QuestionCreateDto question2;
+
+    public static String asJsonString(final Object obj) {
+        try {
+            return new ObjectMapper().writeValueAsString(obj);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @BeforeEach
+    void init() {
+        exercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, 0);
+        question1 = new QuestionCreateDto("this statement is false", exerciseId,
+                List.of(new AnswerInQuestionCreateDto("dis a logical paradox", true)));
+        question2 = new QuestionCreateDto("What month of the year has 28 days?", exerciseId,
+                List.of(new AnswerInQuestionCreateDto("February", false),
+                        new AnswerInQuestionCreateDto("All of them", true)));
+    }
+
+    @Test
+    void testCreateAnswer() throws Exception {
+        var answerCreateDto = new AnswerCreateDto("BA", true, 1);
+        var answerDto = new AnswerDto("BA", true);
+        when(answerFacade.create(ArgumentMatchers.isA(AnswerCreateDto.class))).thenReturn(answerDto);
+
+        mockMvc.perform(post("/answers")
+                        .content(asJsonString(answerCreateDto))
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("$.text", is("BA")))
+                .andExpect(jsonPath("$.correct", is(true)));
+    }
+
+    @Test
+    void testCreateAnswerEmptyText() throws Exception {
+        var incorrect1 = new AnswerInQuestionCreateDto("", false);
+        var createAnswer = new AnswersCreateDto(1, List.of(incorrect1));
+
+        mockMvc.perform(post("/answers")
+                        .content(asJsonString(createAnswer))
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError());
+    }
+
+    @Test
+    void testCreateAnswerMissingText() throws Exception {
+        var prompt = """
+                {
+                "questionId": 1,
+                "answers": [
+                    {
+                    "text": "something",
+                    "correct": false
+                    }
+                ]
+                }
+                """;
+
+        mockMvc.perform(post("/answers")
+                        .content(prompt)
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError());
+    }
+
+    @Test
+    void testCreateAnswerMissingCorrect() throws Exception {
+
+        var prompt = """
+                {
+                "questionId": 1,
+                "answers": [
+                    {
+                    "text": "something"
+                    }
+                ]
+                }
+                """;
+
+        mockMvc.perform(post("/answers")
+                        .content(prompt)
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError());
+    }
+
+    @Test
+    void testUpdate() throws Exception {
+        long id = 1L;
+        var updated = new AnswerDto("dis true", false);
+        when(answerFacade.update(ArgumentMatchers.eq(id), ArgumentMatchers.isA(AnswerCreateDto.class))).thenReturn(updated);
+
+        mockMvc.perform(put("/answers/{id}", id)
+                        .content(asJsonString(updated))
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.text", is("dis true")))
+                .andExpect(jsonPath("$.correct", is(false)));
+    }
+
+    @Test
+    void testUpdateNotFoundAnswer() throws Exception {
+        long id = 1L;
+        var toUpdate = new AnswerCreateDto("dis true", false, 1);
+        when(answerFacade.update(ArgumentMatchers.eq(id), ArgumentMatchers.isA(AnswerCreateDto.class))).thenThrow(new EntityNotFoundException());
+        mockMvc.perform(put("/answers/{id}", id)
+                        .content(asJsonString(toUpdate)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNotFound());
+    }
+
+    @Test
+    void testUpdateEmptyText() throws Exception {
+        var updated = new AnswerCreateDto("", false, 1);
+        mockMvc.perform(put("/answers/1")
+                        .content(asJsonString(updated)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError());
+    }
+
+    @Test
+    void testUpdateMissingField() throws Exception {
+        var updated = """
+                {
+                "correct": false,
+                "questionId": 1
+                }
+                """;
+
+        mockMvc.perform(put("/answers/1")
+                        .content(updated).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError());
+    }
+
+    @Test
+    void testDelete() throws Exception {
+        mockMvc.perform(delete("/answers/1"))
+                .andExpect(status().is2xxSuccessful());
+    }
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerFacadeTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerFacadeTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..f0faeebafdfaa1d1ec4986277f83495f879ef7b0
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerFacadeTest.java
@@ -0,0 +1,53 @@
+package org.fuseri.moduleexercise.answer;
+
+import org.fuseri.model.dto.exercise.AnswerCreateDto;
+import org.fuseri.model.dto.exercise.AnswerDto;
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.fuseri.moduleexercise.question.Question;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+
+import java.util.HashSet;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest
+class AnswerFacadeTest {
+
+    @Autowired
+    private AnswerFacade answerFacade;
+
+    @MockBean
+    private AnswerService answerService;
+
+    @MockBean
+    private AnswerMapper answerMapper;
+
+    private final AnswerDto answerDto = new AnswerDto("name", true);
+    private final AnswerCreateDto answerCreateDto = new AnswerCreateDto("name", true, 1L);
+    private final Question question = new Question("text", new HashSet<>(), new Exercise());
+    private final Answer answer = new Answer("name", true, question);
+
+    @Test
+    void update() {
+        long id = 1L;
+        when(answerMapper.fromCreateDto(answerCreateDto)).thenReturn(answer);
+        when(answerService.update(id, answer)).thenReturn(answer);
+        when(answerMapper.toDto(answer)).thenReturn(answerDto);
+
+        AnswerDto actualDto = answerFacade.update(id, answerCreateDto);
+        assertEquals(answerDto, actualDto);
+    }
+
+    @Test
+    void delete() {
+        long id = 1L;
+        answerFacade.delete(id);
+        verify(answerService).delete(id);
+    }
+
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerRepositoryTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerRepositoryTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..0f567b69064c57addccf48a92a66c5c5c72f3896
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerRepositoryTest.java
@@ -0,0 +1,91 @@
+package org.fuseri.moduleexercise.answer;
+
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.fuseri.moduleexercise.question.Question;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+
+@DataJpaTest
+class AnswerRepositoryTest {
+
+    @Autowired
+    AnswerRepository answerRepository;
+
+    @Autowired
+    TestEntityManager entityManager;
+
+    Exercise exercise = new Exercise("name", "desc", 2, 1L, new HashSet<>());
+
+    Question question = new Question("text", new HashSet<>(), exercise);
+
+    Answer answer = new Answer("text", false, question);
+    Answer answer2 = new Answer("text2", true, question);
+
+    @BeforeEach
+    void init() {
+        entityManager.persist(exercise);
+        entityManager.persist(question);
+    }
+
+    @Test
+    void saveAnswer() {
+        Answer createdAnswer = answerRepository.save(answer);
+
+        Assertions.assertNotNull(createdAnswer);
+        Assertions.assertEquals(answer, createdAnswer);
+    }
+
+    @Test
+    void findByQuestionId() {
+        entityManager.persist(answer);
+        entityManager.flush();
+
+        Answer foundAnswer = answerRepository.findById(answer.getId()).orElse(null);
+
+        Assertions.assertNotNull(foundAnswer);
+        Assertions.assertEquals(foundAnswer, answer);
+    }
+
+    @Test
+    void testFindAllQuestions() {
+        entityManager.persist(exercise);
+        entityManager.persist(question);
+        entityManager.persist(answer);
+        entityManager.persist(answer2);
+        entityManager.flush();
+
+        Page<Answer> coursePage = answerRepository.findAll(PageRequest.of(0, 42));
+
+        Assertions.assertEquals(2, coursePage.getTotalElements());
+        Assertions.assertEquals(coursePage.getContent(), Arrays.asList(answer, answer2));
+    }
+
+    @Test
+    void testFindAllQuestionsEmpty() {
+        Page<Answer> coursePage = answerRepository.findAll(PageRequest.of(0, 42));
+
+        Assertions.assertEquals(0, coursePage.getTotalElements());
+        Assertions.assertEquals(coursePage.getContent(), new ArrayList<>());
+    }
+
+    @Test
+    void testDeleteAnswer() {
+        Long id = entityManager.persist(answer).getId();
+        entityManager.flush();
+
+        answerRepository.deleteById(id);
+
+        Assertions.assertTrue(answerRepository.findById(id).isEmpty());
+    }
+
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerServiceTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerServiceTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..ee53178ff5e7f13e73f3ed97da52421e3c6e3dcb
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerServiceTest.java
@@ -0,0 +1,78 @@
+package org.fuseri.moduleexercise.answer;
+
+import jakarta.persistence.EntityNotFoundException;
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.fuseri.moduleexercise.question.Question;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest
+class AnswerServiceTest {
+
+    @Autowired
+    AnswerService service;
+
+    @MockBean
+    AnswerRepository answerRepository;
+
+    Answer answer;
+    Question question;
+    Exercise exercise;
+
+    @BeforeEach
+    void setup() {
+        exercise = new Exercise("idioms", "exercise on basic idioms", 2, 1L, new HashSet<>());
+        question = new Question("text", new HashSet<>(), exercise);
+        answer = new Answer("text", false, question);
+    }
+
+
+    @Test
+    void create() {
+        when(answerRepository.save(answer)).thenReturn(answer);
+        Answer result = service.create(answer);
+        Assertions.assertEquals(answer, result);
+        verify(answerRepository).save(answer);
+    }
+
+    @Test
+    void notFound() {
+        when(answerRepository.findById(anyLong())).thenReturn(Optional.empty());
+        Assertions.assertThrows(EntityNotFoundException.class, () -> service.find(anyLong()));
+    }
+
+    @Test
+    void find() {
+        when(answerRepository.findById(anyLong())).thenReturn(Optional.of(answer));
+
+        Answer result = service.find(anyLong());
+
+        Assertions.assertEquals(answer, result);
+        verify(answerRepository).findById(anyLong());
+    }
+
+    @Test
+    void findAllByQuestionId() {
+        long id = 1;
+        List<Answer> list = Collections.emptyList();
+
+        when(answerRepository.existsById(id)).thenReturn(true);
+        when(answerRepository.findByQuestionId(id)).thenReturn(list);
+        List<Answer> result = service.findAllByQuestionId(1L);
+
+        Assertions.assertEquals(list, result);
+        verify(answerRepository).findByQuestionId(id);
+    }
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerTest.java
deleted file mode 100644
index da00608e87053cae0b248e864e0a5797d816f9bc..0000000000000000000000000000000000000000
--- a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerTest.java
+++ /dev/null
@@ -1,173 +0,0 @@
-package org.fuseri.moduleexercise.answer;
-
-import com.fasterxml.jackson.core.type.TypeReference;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import org.fuseri.model.dto.exercise.AnswerDto;
-import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
-import org.fuseri.model.dto.exercise.AnswersCreateDto;
-import org.fuseri.model.dto.exercise.ExerciseCreateDto;
-import org.fuseri.model.dto.exercise.ExerciseDto;
-import org.fuseri.model.dto.exercise.QuestionCreateDto;
-import org.fuseri.model.dto.exercise.QuestionDto;
-import org.junit.jupiter.api.Test;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
-import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.http.MediaType;
-import org.springframework.test.web.servlet.MockMvc;
-import java.util.List;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
-
-@SpringBootTest
-@AutoConfigureMockMvc
-public class AnswerTest {
-
-    @Autowired
-    ObjectMapper objectMapper;
-    @Autowired
-    private MockMvc mockMvc;
-
-    public static String asJsonString(final Object obj) {
-        try {
-            return new ObjectMapper().writeValueAsString(obj);
-        } catch (Exception e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    private QuestionDto createQuestion(String id) throws Exception {
-        var question = new QuestionCreateDto("this statement is false", id,
-                List.of(new AnswerInQuestionCreateDto("dis a logical paradox", true)));
-
-
-        var posted = mockMvc.perform(post("/questions")
-                .content(asJsonString(question))
-                .contentType(MediaType.APPLICATION_JSON));
-
-        var cont = posted.andReturn().getResponse().getContentAsString();
-        var res = objectMapper.readValue(cont, QuestionDto.class);
-        return res;
-    }
-
-
-    private String createExercise() {
-        var postExercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, "0");
-
-        String id = "";
-
-        try {
-            var dis = mockMvc.perform(post("/exercises")
-                    .content(asJsonString(postExercise))
-                    .contentType(MediaType.APPLICATION_JSON));
-            var ok = dis.andReturn().getResponse().getContentAsString();
-
-            var ll = objectMapper.readValue(ok, ExerciseDto.class);
-
-            id = ll.getId();
-        } catch (Exception e) {
-            assert (false);
-        }
-        return id;
-    }
-
-
-    @Test
-    void testCreateAnswer() throws Exception {
-
-        List<AnswerDto> res = createAnswer();
-
-        var expected1 = new AnswerDto("True", false);
-        var expected2 = new AnswerDto("False", false);
-
-        assert (res.get(0).equals(expected1));
-        assert (res.get(1).equals(expected2));
-
-    }
-
-    private List<AnswerDto> createAnswer() throws Exception {
-        var exerciseId = createExercise();
-        var question = createQuestion(exerciseId);
-
-        var incorrect1 = new AnswerInQuestionCreateDto("True", false);
-        var incorrect2 = new AnswerInQuestionCreateDto("False", false);
-
-        var createAnswer = new AnswersCreateDto(question.getId(), List.of(incorrect1, incorrect2));
-
-        var posted = mockMvc.perform(post("/answers")
-                .content(asJsonString(createAnswer))
-                .contentType(MediaType.APPLICATION_JSON));
-
-        var asStr = posted.andReturn().getResponse().getContentAsString();
-
-        var res = objectMapper.readValue(asStr, new TypeReference<List<AnswerDto>>() {
-        });
-        return res;
-    }
-
-
-    @Test
-    void getAnswer() throws Exception {
-        var exerciseId = createExercise();
-        var question = createQuestion(exerciseId);
-
-        var gets = mockMvc.perform(get(String.format("/answers/%s", question.getId())));
-
-        var content2 = gets.andReturn().getResponse().getContentAsString();
-
-        var res = objectMapper.readValue(content2, new TypeReference<List<AnswerDto>>() {
-        });
-
-        assert (res.equals(question.getAnswers()));
-
-    }
-
-    @Test
-    void testUpdate() throws Exception {
-
-        var exerciseId = createExercise();
-        var question = createQuestion(exerciseId);
-
-        var incorrect1 = new AnswerInQuestionCreateDto("True", false);
-        var incorrect2 = new AnswerInQuestionCreateDto("False", false);
-
-
-        var createAnswer = new AnswersCreateDto(question.getId(), List.of(incorrect1, incorrect2));
-
-
-        var posted = mockMvc.perform(post("/answers")
-                .content(asJsonString(createAnswer))
-                .contentType(MediaType.APPLICATION_JSON));
-
-        var asStr = posted.andReturn().getResponse().getContentAsString();
-
-        var res = objectMapper.readValue(asStr, new TypeReference<List<AnswerDto>>() {
-        });
-
-
-        var updated = """
-                {
-                  "text": "dis true",
-                  "correct": false,
-                  "questionId": "%s"
-                }
-                """;
-
-
-        updated = String.format(updated, question.getId());
-
-        var puts = mockMvc.perform(put(String.format("/answers/%s", res.get(0).getId()))
-                .content(updated).contentType(MediaType.APPLICATION_JSON));
-
-        var content = puts.andReturn().getResponse().getContentAsString();
-
-        var res2 = objectMapper.readValue(content, AnswerDto.class);
-
-        var expected = new AnswerDto("dis true", false);
-
-        assert res2.equals(expected);
-
-    }
-
-}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseControllerTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseControllerTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..dce5d42843d4279b7813b5a9aa65038c41d245ff
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseControllerTest.java
@@ -0,0 +1,261 @@
+package org.fuseri.moduleexercise.exercise;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import jakarta.persistence.EntityNotFoundException;
+import org.fuseri.model.dto.exercise.ExerciseCreateDto;
+import org.fuseri.model.dto.exercise.ExerciseDto;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentMatchers;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.ArrayList;
+
+import static org.hamcrest.Matchers.is;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+
+@SpringBootTest
+@AutoConfigureMockMvc
+public class ExerciseControllerTest {
+
+    @Autowired
+    ObjectMapper objectMapper;
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockBean
+    ExerciseFacade facade;
+
+    public static String asJsonString(final Object obj) {
+        try {
+            return new ObjectMapper().writeValueAsString(obj);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private ExerciseDto exerciseDto;
+    private ExerciseDto exerciseDto1;
+    private ExerciseDto exerciseDto2;
+    private ExerciseCreateDto exerciseCreateDto;
+    private ExerciseCreateDto exerciseCreateDto1;
+    private ExerciseCreateDto exerciseCreateDto2;
+
+
+    @BeforeEach
+    void init() {
+        exerciseDto = new ExerciseDto();
+        exerciseDto.setName("idioms");
+        exerciseDto.setDescription("exercise on basic idioms");
+        exerciseDto.setDifficulty(2);
+        exerciseDto.setCourseId(0);
+
+        exerciseDto1 = new ExerciseDto();
+        exerciseDto1.setName("idioms1");
+        exerciseDto1.setDescription("exercise on basic idioms");
+        exerciseDto1.setDifficulty(2);
+        exerciseDto1.setCourseId(0);
+
+        exerciseDto2 = new ExerciseDto();
+        exerciseDto2.setName("idioms2");
+        exerciseDto2.setDescription("exercise on basic idioms");
+        exerciseDto2.setDifficulty(1);
+        exerciseDto2.setCourseId(0);
+
+        exerciseCreateDto = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, 0);
+        exerciseCreateDto1 = new ExerciseCreateDto("idioms1", "exercise on intermediate idioms", 2, 0);
+        exerciseCreateDto2 = new ExerciseCreateDto("idioms2", "exercise on basic idioms", 1, 0L);
+    }
+
+    @Test
+    void getExercise() throws Exception {
+        long id = 1L;
+        when(facade.find(id)).thenReturn(exerciseDto);
+        mockMvc.perform(get("/exercises/{id}", id))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.name", is(exerciseCreateDto.getName())))
+                .andExpect(jsonPath("$.description", is(exerciseCreateDto.getDescription())))
+                .andExpect(jsonPath("$.courseId", is((int) exerciseCreateDto.getCourseId())))
+                .andExpect(jsonPath("$.difficulty", is(exerciseCreateDto.getDifficulty())));
+    }
+
+    @Test
+    void testDelete() throws Exception {
+        mockMvc.perform(delete("/exercises/1"))
+                .andExpect(status().is2xxSuccessful());
+    }
+
+    @Test
+    void getExercise_notFound() throws Exception {
+        long id = 1L;
+        when(facade.find(id)).thenThrow(new EntityNotFoundException(""));
+        mockMvc.perform(get("/exercises/{id}", id))
+                .andExpect(status().isNotFound());
+    }
+
+    @Test
+    void FindAll() {
+        when(facade.findAll(0)).thenReturn(new PageImpl<>(new ArrayList<>()));
+        try {
+            var response = mockMvc.perform(get("/exercises").param("page", "0"));
+
+            var dis = response.andExpect(status().isOk())
+                    .andExpect(status().is2xxSuccessful()).andReturn().getResponse().getContentAsString();
+            assertTrue(dis.contains("\"content\":[]"));
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+
+
+    }
+
+    @Test
+    void getFiltered() {
+        when(facade.findByCourseIdAndDifficulty(0, 2, 0)).thenReturn(new PageImpl<>(new ArrayList<>()));
+        try {
+            var filtered = mockMvc.perform(get("/exercises/filter").param("page", "0").param("courseId", "0").param("difficulty", "2"));
+            var content = filtered.andReturn().getResponse().getContentAsString();
+
+            assertTrue(content.contains("\"content\":[]"));
+        } catch (Exception e) {
+            assert (false);
+        }
+    }
+
+    @Test
+    void testCreateExercise() throws Exception {
+        when(facade.create(ArgumentMatchers.isA(ExerciseCreateDto.class))).thenReturn(exerciseDto);
+        mockMvc.perform(post("/exercises").content(asJsonString(exerciseCreateDto)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("$.name").value("idioms"))
+                .andExpect(jsonPath("$.description").value("exercise on basic idioms"))
+                .andExpect(jsonPath("$.difficulty").value(2))
+                .andExpect(jsonPath("$.courseId").value("0")).andReturn().getResponse().getContentAsString();
+    }
+
+    @Test
+    void testCreateExerciseEmptyBody() throws Exception {
+        var postExercise = "";
+        mockMvc.perform(post("/exercises").content((postExercise)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError()).andReturn().getResponse().getContentAsString();
+    }
+
+
+    @Test
+    void testCreateExerciseMissingDesc() throws Exception {
+        var postExercise = """
+                {
+                  "name": "idioms",
+                  "difficulty": 2,
+                  "courseId": 0,
+                }
+                """;
+
+        mockMvc.perform(post("/exercises").content((postExercise)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError()).andReturn().getResponse().getContentAsString();
+    }
+
+    @Test
+    void testCreateExerciseMissingName() throws Exception {
+        var postExercise = """
+                {
+                  "description: "exercise on basic idioms",
+                  "difficulty": 2,
+                  "courseId": 0,
+                }
+                """;
+
+        mockMvc.perform(post("/exercises").content((postExercise)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError()).andReturn().getResponse().getContentAsString();
+    }
+
+    @Test
+    void testCreateExerciseMissingDifficulty() throws Exception {
+        var postExercise = """
+                {
+                  "name": "idioms"
+                  "description: "exercise on basic idioms",
+                  "courseId": 0
+                }
+                """;
+
+        mockMvc.perform(post("/exercises").content((postExercise)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError()).andReturn().getResponse().getContentAsString();
+    }
+
+    @Test
+    void testCreateExerciseMissingCourseId() throws Exception {
+        var postExercise = """
+                {
+                  "name": "idioms"
+                  "description: "exercise on basic idioms",
+                  "difficulty": 0
+                }
+                """;
+
+        mockMvc.perform(post("/exercises").content((postExercise)).contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().is4xxClientError()).andReturn().getResponse().getContentAsString();
+    }
+
+
+    @Test
+    void testUpdate() throws Exception {
+        long id = 1L;
+        when(facade.update(ArgumentMatchers.eq(id), ArgumentMatchers.isA(ExerciseCreateDto.class))).thenReturn(exerciseDto);
+
+        var theId = String.format("/exercises/%d", id);
+        var dis = mockMvc.perform(put(theId).content(asJsonString(exerciseCreateDto)).contentType(MediaType.APPLICATION_JSON));
+
+        dis.andExpect(status().isOk()).andExpect(jsonPath("$.name", is(exerciseDto.getName())))
+                .andExpect(jsonPath("$.difficulty", is(exerciseDto.getDifficulty())))
+                .andExpect(jsonPath("$.description", is(exerciseDto.getDescription())));
+    }
+
+    @Test
+    void testUpdateNotFound() {
+        long id = 9999L;
+        when(facade.update(ArgumentMatchers.eq(id), ArgumentMatchers.isA(ExerciseCreateDto.class))).thenThrow(new EntityNotFoundException());
+
+        try {
+            var theId = String.format("/exercises/%d", id);
+            mockMvc.perform(put(theId).content(asJsonString(exerciseCreateDto)).contentType(MediaType.APPLICATION_JSON))
+                    .andExpect(status().isNotFound());
+
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Test
+    void testUpdateIncorrectBody() {
+        long id = 1L;
+        var content = """
+                {
+                  "description": "exercise on basic idioms",
+                  "difficulty": 2,
+                  "courseId": 0
+                }
+                """;
+        try {
+            var theId = String.format("/exercises/%d", id);
+            mockMvc.perform(put(theId).content(content).contentType(MediaType.APPLICATION_JSON))
+                    .andExpect(status().is4xxClientError());
+
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseFacadeTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseFacadeTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..0be6f3770b15f6963a2a3200e888efd8115cd4c3
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseFacadeTest.java
@@ -0,0 +1,99 @@
+package org.fuseri.moduleexercise.exercise;
+
+import org.fuseri.model.dto.exercise.ExerciseCreateDto;
+import org.fuseri.model.dto.exercise.ExerciseDto;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest
+@AutoConfigureMockMvc
+class ExerciseFacadeTest {
+
+    @Autowired
+    ExerciseFacade exerciseFacade;
+
+    @MockBean
+    ExerciseService exerciseService;
+
+    @MockBean
+    ExerciseMapper exerciseMapper;
+
+    private final ExerciseDto exerciseDto = new ExerciseDto();
+
+    private final ExerciseCreateDto exerciseCreateDto = new ExerciseCreateDto("name", "desc", 2, 1);
+
+    private final Exercise exercise = new Exercise();
+
+    @Test
+    void create() {
+        when(exerciseMapper.fromCreateDto(exerciseCreateDto)).thenReturn(exercise);
+        when(exerciseService.create(exercise)).thenReturn(exercise);
+        when(exerciseMapper.toDto(exercise)).thenReturn(exerciseDto);
+
+        ExerciseDto actualDto = exerciseFacade.create(exerciseCreateDto);
+
+        assertEquals(exerciseDto, actualDto);
+    }
+
+    @Test
+    void testFindById() {
+        long id = 1L;
+
+        when(exerciseService.find(id)).thenReturn(exercise);
+        when(exerciseMapper.toDto(exercise)).thenReturn(exerciseDto);
+
+        ExerciseDto actualDto = exerciseFacade.find(id);
+
+        assertNotNull(actualDto);
+        assertEquals(exerciseDto, actualDto);
+    }
+
+    @Test
+    void testFindAll() {
+        int page = 0;
+        Pageable pageable = PageRequest.of(0, 10);
+        Page<Exercise> exercisePage = new PageImpl<>(List.of(exercise), pageable, 0);
+        Page<ExerciseDto> expectedPageDto = new PageImpl<>(List.of(exerciseDto));
+
+        when(exerciseService.findAll(page)).thenReturn(exercisePage);
+        when(exerciseMapper.toDtoPage(exercisePage)).thenReturn(expectedPageDto);
+
+        Page<ExerciseDto> actualPageDto = exerciseFacade.findAll(page);
+
+        assertEquals(expectedPageDto, actualPageDto);
+    }
+
+    @Test
+    void update() {
+        long id = 1L;
+        when(exerciseMapper.fromCreateDto(exerciseCreateDto)).thenReturn(exercise);
+        when(exerciseService.update(id, exercise)).thenReturn(exercise);
+        when(exerciseMapper.toDto(exercise)).thenReturn(exerciseDto);
+
+        ExerciseDto actualDto = exerciseFacade.update(id, exerciseCreateDto);
+
+        assertEquals(exerciseDto, actualDto);
+    }
+
+    @Test
+    void testDelete() {
+        long id = 1L;
+        exerciseFacade.delete(id);
+        verify(exerciseService).delete(id);
+    }
+
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseRepositoryTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseRepositoryTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..1d8eec54a05e1384cfed5cb5aa136f5c680410ce
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseRepositoryTest.java
@@ -0,0 +1,80 @@
+package org.fuseri.moduleexercise.exercise;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+
+import java.util.Arrays;
+import java.util.HashSet;
+
+@DataJpaTest
+class ExerciseRepositoryTest {
+
+    @Autowired
+    ExerciseRepository exerciseRepository;
+
+    @Autowired
+    TestEntityManager entityManager;
+
+    Exercise exercise = new Exercise("name", "desc", 2, 1L, new HashSet<>());
+
+    @Test
+    void saveExercise() {
+        Exercise saved = exerciseRepository.save(exercise);
+
+        Assertions.assertNotNull(saved);
+        Assertions.assertEquals(exercise, saved);
+    }
+
+    @Test
+    void findById() {
+        entityManager.persist(exercise);
+        entityManager.flush();
+
+        Exercise found = exerciseRepository.findById(exercise.getId()).orElse(null);
+
+        Assertions.assertNotNull(found);
+        Assertions.assertEquals(found, exercise);
+    }
+
+
+    @Test
+    void findByCourseIdAndDifficulty() {
+        entityManager.persist(exercise);
+        entityManager.flush();
+
+        Page<Exercise> found = exerciseRepository.findByCourseIdAndDifficulty(1L, 2, PageRequest.of(0, 10));
+
+        Assertions.assertEquals(1, found.getTotalElements());
+        Assertions.assertEquals(found.getContent().get(0), exercise);
+    }
+
+    @Test
+    void testFindAllExercises() {
+        Exercise exercise1 = new Exercise();
+
+        entityManager.persist(exercise);
+        entityManager.persist(exercise1);
+        entityManager.flush();
+
+        Page<Exercise> coursePage = exerciseRepository.findAll(PageRequest.of(0, 42));
+
+        Assertions.assertEquals(2, coursePage.getTotalElements());
+        Assertions.assertEquals(coursePage.getContent(), Arrays.asList(exercise, exercise1));
+    }
+
+    @Test
+    void testDeleteExercise() {
+        Long id = entityManager.persist(exercise).getId();
+        entityManager.flush();
+
+        exerciseRepository.deleteById(id);
+
+        Assertions.assertTrue(exerciseRepository.findById(id).isEmpty());
+    }
+
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseServiceTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseServiceTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..7d54a6cc2869ee3e00af9abb67933de0ca71a9c6
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseServiceTest.java
@@ -0,0 +1,111 @@
+package org.fuseri.moduleexercise.exercise;
+
+import jakarta.persistence.EntityNotFoundException;
+import org.fuseri.model.dto.exercise.ExerciseCreateDto;
+import org.fuseri.moduleexercise.question.Question;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Optional;
+
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+
+@SpringBootTest
+class ExerciseServiceTest {
+
+    @MockBean
+    ExerciseRepository exerciseRepository;
+
+    @Autowired
+    ExerciseService exerciseService;
+
+    Exercise exercise;
+    ExerciseCreateDto exercise2;
+    ExerciseCreateDto exercise3;
+
+    @BeforeEach
+    void setup() {
+        exercise = new Exercise("idioms", "exercise on basic idioms", 2, 1L, new HashSet<>());
+        exercise2 = new ExerciseCreateDto("idioms1", "exercise on intermediate idioms", 2, 0);
+        exercise3 = new ExerciseCreateDto("idioms2", "exercise on basic idioms", 1, 0L);
+    }
+
+    @Test
+    void create() {
+        when(exerciseRepository.save(exercise)).thenReturn(exercise);
+        Exercise result = exerciseService.create(exercise);
+        Assertions.assertEquals(exercise, result);
+        verify(exerciseRepository).save(exercise);
+    }
+
+    @Test
+    void notFound() {
+        when(exerciseRepository.findById(anyLong())).thenReturn(Optional.empty());
+
+        Assertions.assertThrows(EntityNotFoundException.class, () -> exerciseService.find(anyLong()));
+    }
+
+    @Test
+    void find() {
+        when(exerciseRepository.findById(anyLong())).thenReturn(Optional.of(exercise));
+
+        Exercise result = exerciseService.find(anyLong());
+
+        Assertions.assertEquals(exercise, result);
+        verify(exerciseRepository).findById(anyLong());
+    }
+
+    @Test
+    void findAll() {
+        Pageable pageable = PageRequest.of(0, 10);
+        Page<Exercise> page = new PageImpl<>(Collections.emptyList(), pageable, 0);
+
+        when(exerciseRepository.findAll(pageable)).thenReturn(page);
+        Page<Exercise> result = exerciseService.findAll(0);
+
+        Assertions.assertEquals(page, result);
+        verify(exerciseRepository).findAll(pageable);
+    }
+
+    @Test
+    void findByCourseIdAndDifficulty() {
+        PageRequest pageable = PageRequest.of(0, 10);
+        Page<Exercise> page = new PageImpl<>(Collections.emptyList(), pageable, 0);
+
+        when(exerciseRepository.findByCourseIdAndDifficulty(1L, 2, pageable)).thenReturn(page);
+
+        Page<Exercise> result = exerciseService.findByCourseIdAndDifficulty(1L, 2, 0);
+
+        Assertions.assertEquals(page, result);
+        verify(exerciseRepository).findByCourseIdAndDifficulty(1L, 2, pageable);
+    }
+
+
+    @Test
+    void getQuestions() {
+        PageRequest pageable = PageRequest.of(0, 10);
+        Page<Question> page = new PageImpl<>(Collections.emptyList(), pageable, 0);
+
+        when(exerciseRepository.getQuestions(pageable, 1L)).thenReturn(page);
+        when(exerciseRepository.existsById(1L)).thenReturn(true);
+
+
+        Page<Question> result = exerciseService.getQuestions(1L, 0);
+
+        Assertions.assertEquals(page, result);
+        verify(exerciseRepository).getQuestions(pageable, 1L);
+    }
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseTest.java
deleted file mode 100644
index a634b41941ff09a1d6fa1a82125c2015c3206bf1..0000000000000000000000000000000000000000
--- a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseTest.java
+++ /dev/null
@@ -1,161 +0,0 @@
-package org.fuseri.moduleexercise.exercise;
-
-import com.fasterxml.jackson.core.type.TypeReference;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import org.fuseri.model.dto.common.Result;
-import org.fuseri.model.dto.exercise.ExerciseCreateDto;
-import org.fuseri.model.dto.exercise.ExerciseDto;
-import org.junit.jupiter.api.Test;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
-import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.http.MediaType;
-import org.springframework.test.web.servlet.MockMvc;
-
-import java.util.Map;
-
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
-
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
-
-
-@SpringBootTest
-@AutoConfigureMockMvc
-public class ExerciseTest {
-    @Autowired
-    ObjectMapper objectMapper;
-    @Autowired
-    private MockMvc mockMvc;
-
-    public static String asJsonString(final Object obj) {
-        try {
-            return new ObjectMapper().writeValueAsString(obj);
-        } catch (Exception e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-
-    @Test
-    void getExercise() {
-        var postExercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, "0");
-
-        String id = "";
-
-        try {
-            var dis = mockMvc.perform(post("/exercises").content(asJsonString(postExercise)).contentType(MediaType.APPLICATION_JSON));
-            var ok = dis.andReturn().getResponse().getContentAsString();
-
-            var ll = objectMapper.readValue(ok, ExerciseDto.class);
-
-            id = ll.getId();
-        } catch (Exception e) {
-            assert (false);
-        }
-
-
-        try {
-            var theId = String.format("/exercises/%s", id);
-            var smth = mockMvc.perform(get(theId));
-
-        } catch (Exception e) {
-            //do absolutely nothing
-        }
-    }
-
-    @Test
-    void getFiltered() {
-
-
-        var postExercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 0, "0");
-        var postExercise1 = new ExerciseCreateDto("idioms1", "exercise on basic idioms", 0, "0");
-        var postExercise2 = new ExerciseCreateDto("idioms2", "exercise on basic idioms", 1, "0");
-
-        try {
-            var exercise1 = mockMvc.perform(post("/exercises").content(asJsonString(postExercise)).contentType(MediaType.APPLICATION_JSON));
-
-            var exercise2 = mockMvc.perform(post("/exercises").content(asJsonString(postExercise1)).contentType(MediaType.APPLICATION_JSON));
-            var exercise3 = mockMvc.perform(post("/exercises").content(asJsonString(postExercise2)).contentType(MediaType.APPLICATION_JSON));
-        } catch (Exception e) {
-            //do absolutly nothing
-        }
-
-
-        Map<String, String> params;
-
-        try {
-            var filtered = mockMvc.perform(get("/exercises/filter").param("page", "0").param("courseId", "0").param("difficulty", "0"));
-
-            var content = filtered.andReturn().getResponse().getContentAsString();
-
-            var res = objectMapper.readValue(content, new TypeReference<Result<ExerciseDto>>() {
-            });
-
-            assert (res.getTotal() == 2);
-        } catch (Exception e) {
-            assert (false);
-        }
-    }
-
-    @Test
-    void testCreateExercise() throws Exception {
-        var expectedResponse = new ExerciseDto();
-        var postExercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, "0");
-
-        mockMvc.perform(post("/exercises").content(asJsonString(postExercise)).contentType(MediaType.APPLICATION_JSON)).andExpect(status().isOk()).andExpect(jsonPath("$.name").value("idioms")).andExpect(jsonPath("$.description").value("exercise on basic idioms")).andExpect(jsonPath("$.difficulty").value(2)).andExpect(jsonPath("$.courseId").value("0")).andReturn().getResponse().getContentAsString();
-    }
-
-    @Test
-    void testUpdate() {
-        var postExercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, "0");
-
-        String id = "";
-
-        try {
-            var dis = mockMvc.perform(post("/exercises").content(asJsonString(postExercise)).contentType(MediaType.APPLICATION_JSON));
-            var ok = dis.andReturn().getResponse().getContentAsString();
-
-            var ll = objectMapper.readValue(ok, ExerciseDto.class);
-
-            id = ll.getId();
-        } catch (Exception e) {
-            assert (false);
-        }
-
-        var expectedExercise = new ExerciseDto();
-        expectedExercise.setId(id);
-        expectedExercise.setName("idioms");
-        expectedExercise.setDifficulty(2);
-        expectedExercise.setCourseId("idioms");
-        expectedExercise.setDescription("exercise on basic idioms");
-
-        var content = """
-                {
-                  "name": "idioms",
-                  "description": "exercise on basic idioms",
-                  "difficulty": 2,
-                  "courseId": "idioms"
-                }
-                """;
-
-
-        try {
-            var theId = String.format("/exercises/%s", id);
-            var dis = mockMvc.perform(put(theId).content(content).contentType(MediaType.APPLICATION_JSON));
-
-            var str = dis.andReturn().getResponse().getContentAsString();
-
-            var res = objectMapper.readValue(str, ExerciseDto.class);
-
-            assert res.equals(expectedExercise);
-
-        } catch (Exception e) {
-            throw new RuntimeException(e);
-        }
-
-    }
-
-}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionFacadeTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionFacadeTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..33e1ca0a8f8b9ff86d3ec16f12a5df86738c5d29
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionFacadeTest.java
@@ -0,0 +1,125 @@
+package org.fuseri.moduleexercise.question;
+
+
+import org.fuseri.model.dto.exercise.AnswerDto;
+import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
+import org.fuseri.model.dto.exercise.QuestionCreateDto;
+import org.fuseri.model.dto.exercise.QuestionDto;
+import org.fuseri.model.dto.exercise.QuestionUpdateDto;
+import org.fuseri.moduleexercise.answer.Answer;
+import org.fuseri.moduleexercise.answer.AnswerMapper;
+import org.fuseri.moduleexercise.answer.AnswerService;
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest
+class QuestionFacadeTest {
+
+    @Autowired
+    QuestionFacade questionFacade;
+
+    @MockBean
+    QuestionService questionService;
+
+    @MockBean
+    AnswerService answerService;
+
+    @MockBean
+    QuestionMapper questionMapper;
+
+    @MockBean
+    AnswerMapper answerMapper;
+
+    private final QuestionDto questionDto = new QuestionDto();
+
+    private final QuestionCreateDto questionCreateDto = new QuestionCreateDto("name", 1L, new ArrayList<>());
+
+    private final QuestionUpdateDto questionUpdateDto = QuestionUpdateDto.builder().build();
+
+    private final Exercise exercise = new Exercise();
+
+    private final Question question = new Question("text", new HashSet<>(), exercise);
+    Set<Answer> answers = new HashSet<>(List.of(new Answer("BA", true, question)));
+
+    @Test
+    void create() {
+        when(questionMapper.fromCreateDto(questionCreateDto)).thenReturn(question);
+        when(questionService.create(question)).thenReturn(question);
+        when(questionMapper.toDto(question)).thenReturn(questionDto);
+
+        QuestionDto actualDto = questionFacade.create(questionCreateDto);
+
+        assertEquals(questionDto, actualDto);
+    }
+
+    @Test
+    void find() {
+        long id = 1L;
+
+        when(questionService.find(id)).thenReturn(question);
+        when(questionMapper.toDto(question)).thenReturn(questionDto);
+
+        QuestionDto actualDto = questionFacade.find(id);
+
+        assertNotNull(actualDto);
+        assertEquals(questionDto, actualDto);
+    }
+
+    @Test
+    void patchUpdate() {
+        long id = 1L;
+        when(questionMapper.fromUpdateDto(questionUpdateDto)).thenReturn(question);
+        when(questionService.patchUpdateWithoutAnswers(id, question)).thenReturn(question);
+        when(questionMapper.toDto(question)).thenReturn(questionDto);
+        QuestionDto actualDto = questionFacade.patchUpdate(id, questionUpdateDto);
+
+        assertEquals(questionDto, actualDto);
+    }
+
+    @Test
+    void testDelete() {
+        long id = 1L;
+        when(questionService.find(id)).thenReturn(question);
+
+        questionFacade.delete(id);
+        verify(questionService).delete(id);
+    }
+
+    @Test
+    void getQuestionAnswers() {
+        long id = 1L;
+        List<Answer> answers = List.of(new Answer("BA", true, question));
+        List<AnswerDto> answerDtos = List.of(new AnswerDto("BA", true));
+        when(answerMapper.toDtoList(answers)).thenReturn(answerDtos);
+        when(answerService.findAllByQuestionId(id)).thenReturn(answers);
+        var actualAnswers = questionFacade.getQuestionAnswers(id);
+        assertEquals(answerDtos, actualAnswers);
+    }
+
+    @Test
+    void addAnswers() {
+        long id = 1L;
+        question.setAnswers(answers);
+        List<AnswerInQuestionCreateDto> answerDtos = List.of(new AnswerInQuestionCreateDto("BA", true));
+        QuestionDto questionDtoAnswers = new QuestionDto(question.getText(), question.getExercise().getId(), List.of(new AnswerDto("BA", true)));
+
+        when(answerMapper.fromCreateDtoList(answerDtos)).thenReturn(answers);
+        when(questionService.addAnswers(id, answers)).thenReturn(question);
+        when(questionMapper.toDto(question)).thenReturn(questionDtoAnswers);
+        QuestionDto actualQuestionDto = questionFacade.addAnswers(id, answerDtos);
+        assertEquals(questionDtoAnswers, actualQuestionDto);
+    }
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionRepositoryTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionRepositoryTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..3c0eb33e9b5b83677709c5d43c1f8c47d94db32d
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionRepositoryTest.java
@@ -0,0 +1,88 @@
+package org.fuseri.moduleexercise.question;
+
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.fuseri.moduleexercise.exercise.ExerciseRepository;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+
+@DataJpaTest
+public class QuestionRepositoryTest {
+
+    @Autowired
+    QuestionRepository repository;
+
+    @Autowired
+    ExerciseRepository exerciseRepository;
+
+    @Autowired
+    TestEntityManager entityManager;
+
+
+    Exercise exercise = new Exercise("name","desc",2,1L,new HashSet<>());
+
+    Question question = new Question("text",new HashSet<>(),exercise);
+    Question question2 = new Question("text2",new HashSet<>(),exercise);
+
+    @BeforeEach
+    void init() {
+        exerciseRepository.save(exercise);
+    }
+
+    @Test
+    void saveQuestion() {
+        Question saved = repository.save(question);
+
+        Assertions.assertNotNull(saved);
+        Assertions.assertEquals(question, saved);
+    }
+
+    @Test
+    void findById() {
+        entityManager.persist(question);
+        entityManager.flush();
+
+        Question found = repository.findById(question.getId()).orElse(null);
+
+        Assertions.assertNotNull(found);
+        Assertions.assertEquals(found, question);
+    }
+
+
+    @Test
+    void testFindAllQuestions() {
+        entityManager.persist(question);
+        entityManager.persist(question2);
+
+        Page<Question> coursePage = repository.findAll(PageRequest.of(0, 42));
+
+        Assertions.assertEquals(2, coursePage.getTotalElements());
+        Assertions.assertEquals(coursePage.getContent(), Arrays.asList(question, question2));
+    }
+    @Test
+    void testFindAllQuestionsEmpty() {
+        Page<Question> coursePage = repository.findAll(PageRequest.of(0, 42));
+
+        Assertions.assertEquals(0, coursePage.getTotalElements());
+        Assertions.assertEquals(coursePage.getContent(), new ArrayList<>());
+    }
+
+    @Test
+    void testDeleteQuestion() {
+        Long id = entityManager.persist(question).getId();
+        entityManager.flush();
+
+        repository.deleteById(id);
+
+        Assertions.assertTrue(repository.findById(id).isEmpty());
+    }
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionServiceTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionServiceTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..298510e1ea93958b62dc321e70031f2c8d0c2ab3
--- /dev/null
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionServiceTest.java
@@ -0,0 +1,83 @@
+package org.fuseri.moduleexercise.question;
+
+import jakarta.persistence.EntityNotFoundException;
+import org.fuseri.moduleexercise.answer.Answer;
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import java.util.HashSet;
+import java.util.Optional;
+import java.util.Set;
+
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@SpringBootTest
+class QuestionServiceTest {
+
+    @MockBean
+    QuestionRepository questionRepository;
+
+    @Autowired
+    QuestionService questionService;
+
+    Exercise exercise;
+    Question question;
+    Question question1;
+
+    @BeforeEach
+    void setup() {
+        exercise = new Exercise("idioms", "exercise on basic idioms",2,1L,new HashSet<>());
+        question = new Question("text",new HashSet<>(),exercise);
+        question1 = new Question("text2",new HashSet<>(),exercise);
+    }
+
+
+    @Test
+    void create() {
+        when(questionRepository.save(question)).thenReturn(question);
+        Question result = questionService.create(question);
+        Assertions.assertEquals(question, result);
+        verify(questionRepository).save(question);
+    }
+
+    @Test
+    void notFound() {
+        when(questionRepository.findById(anyLong())).thenReturn(Optional.empty());
+
+        Assertions.assertThrows(EntityNotFoundException.class, () -> questionService.find(anyLong()));
+    }
+
+    @Test
+    void find() {
+        when(questionRepository.findById(anyLong())).thenReturn(Optional.of(question));
+
+        Question result = questionService.find(anyLong());
+
+        Assertions.assertEquals(question, result);
+        verify(questionRepository).findById(anyLong());
+    }
+
+    @Test
+    void patchUpdateWithoutAnswers() {
+        when(questionRepository.findById(anyLong())).thenReturn(Optional.of(question));
+        when(questionRepository.save(question)).thenReturn(question);
+        Question result = questionService.patchUpdateWithoutAnswers(anyLong(), question);
+        Assertions.assertEquals(question, result);
+    }
+
+    @Test
+    void addAnswers() {
+        Set<Answer> answers = Set.of(new Answer("BA", true, question));
+        question.setAnswers(answers);
+        when(questionRepository.findById(anyLong())).thenReturn(Optional.of(question));
+        when(questionRepository.save(question)).thenReturn(question);
+        Question result = questionService.patchUpdateWithoutAnswers(anyLong(), question);
+        Assertions.assertEquals(question, result);
+    }
+}
diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionTest.java
index a099ff7c8cf058e033931222d5c76469ac40003e..8383971d23f186ac9740263ebb47ed4ab303be1f 100644
--- a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionTest.java
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionTest.java
@@ -1,27 +1,41 @@
 package org.fuseri.moduleexercise.question;
 
-import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import org.fuseri.model.dto.common.Result;
+import jakarta.persistence.EntityNotFoundException;
 import org.fuseri.model.dto.exercise.AnswerDto;
 import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
 import org.fuseri.model.dto.exercise.ExerciseCreateDto;
-import org.fuseri.model.dto.exercise.ExerciseDto;
 import org.fuseri.model.dto.exercise.QuestionCreateDto;
 import org.fuseri.model.dto.exercise.QuestionDto;
+import org.fuseri.model.dto.exercise.QuestionUpdateDto;
+import org.fuseri.moduleexercise.exercise.Exercise;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentMatcher;
+import org.mockito.ArgumentMatchers;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
 import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
 import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.ResultActions;
 
+import static org.hamcrest.Matchers.is;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
 
 
 @SpringBootTest
@@ -33,6 +47,11 @@ public class QuestionTest {
     @Autowired
     private MockMvc mockMvc;
 
+    @MockBean
+    QuestionFacade facade;
+
+    private QuestionDto qston;
+
     public static String asJsonString(final Object obj) {
         try {
             return new ObjectMapper().writeValueAsString(obj);
@@ -41,113 +60,146 @@ public class QuestionTest {
         }
     }
 
-    @Test
-    void testCreateQuestion() throws Exception {
-        String id = createExercise();
-        var answr = new AnswerDto("dis a logical paradox", true);
-        QuestionDto res = createQuestion(id);
-        var expected = new QuestionDto();
-        expected.setAnswers(List.of(answr));
-        expected.setExerciseId(id);
-        expected.setId(res.getId());
-        expected.setText("this statement is false");
-
-        assert expected.equals(res);
+    private void createExercise() {
+        var postExercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, 0L);
+        var postExercise2 = new ExerciseCreateDto("riddles", "simple english riddles", 2, 0L);
+        try {
+            mockMvc.perform(post("/exercises").content(asJsonString(postExercise)).contentType(MediaType.APPLICATION_JSON));
+            mockMvc.perform(post("/exercises").content(asJsonString(postExercise2)).contentType(MediaType.APPLICATION_JSON));
+
+        } catch (Exception e) {
+            assert (false);
+        }
     }
 
-    private QuestionDto createQuestion(String id) throws Exception {
+    @BeforeEach
+    void init() {
+//        createExercise();
+
+        qston = new QuestionDto("\"what is the meaning of: costs an arm and leg\"",1,new ArrayList<>());
+        long id = 2;
+
         var question = new QuestionCreateDto("this statement is false", id, List.of(new AnswerInQuestionCreateDto("dis a logical paradox", true)));
+        var question2 = new QuestionCreateDto("What month of the year has 28 days?", id, List.of(new AnswerInQuestionCreateDto("February", false), new AnswerInQuestionCreateDto("All of them", true)));
+        ResultActions posted = null;
+    }
 
 
+    @Test
+    void testCreateQuestion() throws Exception {
+        var exerciseId = 1L;
+        var question = new QuestionCreateDto("what is the meaning of: costs an arm and leg", exerciseId, List.of(new AnswerInQuestionCreateDto("dis very expencive", true), new AnswerInQuestionCreateDto("FMA refference", false)));
+        when(facade.create(ArgumentMatchers.isA(QuestionCreateDto.class))).thenReturn(qston);
         var posted = mockMvc.perform(post("/questions").content(asJsonString(question)).contentType(MediaType.APPLICATION_JSON));
 
+        posted.andExpect(status().isCreated())
+                .andExpect(jsonPath("$.text", is(qston.getText())))
+                .andExpect(jsonPath("$.exerciseId", is((int)qston.getExerciseId())));
 
-        var cont = posted.andReturn().getResponse().getContentAsString();
-        var res = objectMapper.readValue(cont, QuestionDto.class);
-        return res;
     }
 
-    private String createExercise() {
-        var postExercise = new ExerciseCreateDto("idioms", "exercise on basic idioms", 2, "0");
-
-        String id = "";
-
-        try {
-            var dis = mockMvc.perform(post("/exercises").content(asJsonString(postExercise)).contentType(MediaType.APPLICATION_JSON));
-            var ok = dis.andReturn().getResponse().getContentAsString();
+    @Test
+    void testCreateQuestionEmptyQuestions() throws Exception {
+        var prompt = """
+                {
+                "text": "this is a question without exercise Id",
+                "exerciseId": 1,
+                "answers": []
+                }
+                """;
 
-            var ll = objectMapper.readValue(ok, ExerciseDto.class);
+        var posted = mockMvc.perform(post("/questions").content(prompt).contentType(MediaType.APPLICATION_JSON));
 
-            id = ll.getId();
-        } catch (Exception e) {
-            assert (false);
-        }
-        return id;
+        posted.andExpect(status().isCreated());
     }
 
 
     @Test
-    void getQuestion() throws Exception {
-
+    void testCreateQuestionEmptyField() throws Exception {
+        var exerciseId = 1L;
+        var question = new QuestionCreateDto("", exerciseId, List.of(new AnswerInQuestionCreateDto("dis very expencive", true), new AnswerInQuestionCreateDto("FMA refference", false)));
+        var posted = mockMvc.perform(post("/questions").content(asJsonString(question)).contentType(MediaType.APPLICATION_JSON));
 
-        String exerciseId = createExercise();
-        var question = createQuestion(exerciseId);
+        posted.andExpect(status().is4xxClientError());
+    }
 
-        var theId = String.format("/questions/%s", question.getId());
+    @Test
+    void testCreateQuestionMissingField() throws Exception {
+        var prompt = """
+                {
+                "text": "this is a question without exercise Id,
+                "answers" : []
+                }
+                """;
 
+        var posted = mockMvc.perform(post("/questions").content(prompt).contentType(MediaType.APPLICATION_JSON));
 
-        var gets = mockMvc.perform(get(theId));
+        posted.andExpect(status().is4xxClientError());
+    }
 
-        var content = gets.andReturn().getResponse().getContentAsString();
-        var res = objectMapper.readValue(content, QuestionDto.class);
+    private QuestionDto createQuestion(long id) throws Exception {
+        var question = new QuestionCreateDto("this statement is false", id, List.of(new AnswerInQuestionCreateDto("dis a logical paradox", true)));
+        var posted = mockMvc.perform(post("/questions").content(asJsonString(question)).contentType(MediaType.APPLICATION_JSON));
+        var cont = posted.andReturn().getResponse().getContentAsString();
+        var res = objectMapper.readValue(cont, QuestionDto.class);
+        return res;
+    }
 
-        assert res.equals(question);
 
+    @Test
+    void getQuestion() throws Exception {
+        var question = new QuestionDto("this statement is false",1L,new ArrayList<>());
+        when(facade.find(1)).thenReturn(question);
+        var gets = mockMvc.perform(get("/questions/1"));
+        gets.andExpect(status().isOk()).andExpect(jsonPath("$.text", is("this statement is false")));
     }
 
     @Test
-    void getByExercise() throws Exception {
-
-        var exerciseId = createExercise();
-        var question = createQuestion(exerciseId);
+    void getQuestionNotFound() throws Exception {
+        when(facade.find(9999)).thenThrow(new EntityNotFoundException());
+        var gets = mockMvc.perform(get("/questions/9999"));
+        gets.andExpect(status().isNotFound());
+    }
 
-        var theId = String.format("/questions/exercise/%s", exerciseId);
 
-        var smth = mockMvc.perform(get(theId).param("page", "0"));
+    @Test
+    void getAnswer() throws Exception {
 
-        var content = smth.andReturn().getResponse().getContentAsString();
 
-        var res = objectMapper.readValue(content, new TypeReference<Result<QuestionDto>>() {
-        });
+        var sss = List.of(new AnswerDto("February", false), new AnswerDto("All of them", true));
+        when(facade.getQuestionAnswers(2)).thenReturn(sss);
+        var gets = mockMvc.perform(get("/questions/2/answers"));
+        gets.andExpect(status().isOk())
+                .andExpect(jsonPath("$[0].text", is("February")))
+                .andExpect(jsonPath("$[1].text", is("All of them")));
 
-        Map<String, String> params;
 
-        assert (res.getItems().get(0).equals(question));
     }
 
     @Test
     void TestUpdate() throws Exception {
-        String id = createExercise();
-        var question = createQuestion(id);
-
         var updated = """
                 {
                   "text": "wat a paradox?",
-                  "exerciseId": "%s"
+                  "exerciseId": "1"
                 }
                 """;
 
-        updated = String.format(updated, id);
-
-        var smth = mockMvc.perform(put(String.format("/questions/%s", question.getId())).content(updated).contentType(MediaType.APPLICATION_JSON));
-
-        var content = smth.andReturn().getResponse().getContentAsString();
-
-        var res = objectMapper.readValue(content, QuestionDto.class);
+        var question = new QuestionDto("wat a paradox?",1,new ArrayList<>());
 
-        question.setText("wat a paradox?");
+        when(facade.patchUpdate(ArgumentMatchers.eq(1), ArgumentMatchers.isA(QuestionUpdateDto.class))).thenReturn(question);
+        var gets = mockMvc.perform(put("/questions/1").content(updated).contentType(MediaType.APPLICATION_JSON));
 
-        assert (question.equals(res));
+        gets.andExpect(status().isOk());
+    }
 
+@Test
+    void deleteExisting() {
+    try {
+        mockMvc.perform(delete("/questions/1")).andExpect(status().isNoContent());
+    } catch (Exception e) {
+        throw new RuntimeException(e);
     }
 }
+
+}
diff --git a/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/course/CourseControllerTest.java b/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/course/CourseControllerTest.java
index 21ed4e68ecce1e1025dc0f14f1525345589a0e36..b75d751ab035fcb4c53014a3fac3ecf41b990508 100644
--- a/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/course/CourseControllerTest.java
+++ b/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/course/CourseControllerTest.java
@@ -218,9 +218,10 @@ public class CourseControllerTest {
                 .andExpect(status().isOk())
                 .andExpect(jsonPath("$.name").value("english b2 course"))
                 .andExpect(jsonPath("$.capacity").value(10))
-                .andExpect(jsonPath("$.language").value("ENGLISH"))
-                .andExpect(jsonPath("$.proficiency").value("B2"))
-                .andExpect(jsonPath("$.studentIds").exists());
+                .andExpect(jsonPath("$.languageTypeDto").value("ENGLISH"))
+                .andExpect(jsonPath("$.proficiencyLevelDto").value("B2"))
+                .andExpect(jsonPath("$.studentIds").value(student.getId()))
+                .andReturn().getResponse().getContentAsString();
     }
 
     @Test
diff --git a/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/user/UserControllerTest.java b/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/user/UserControllerTest.java
index 59f5032bf8a1fe520fa1160415230843c3d2850f..112bbb53472fd0e906ad0068f6ee335e0b0cc17e 100644
--- a/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/user/UserControllerTest.java
+++ b/application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/user/UserControllerTest.java
@@ -121,7 +121,7 @@ class UserControllerTest {
                         .contentType(MediaType.APPLICATION_JSON))
                 .andExpect(status().isOk()).andReturn().getResponse().getContentAsString();
 
-        Long id = objectMapper.readValue(response, UserDto.class).getId();
+        String id = objectMapper.readValue(response, UserDto.class).getId();
 
         mockMvc.perform(get("/users/{id}", id))
                 .andExpect(status().isOk())
@@ -142,7 +142,7 @@ class UserControllerTest {
                         .contentType(MediaType.APPLICATION_JSON))
                 .andExpect(status().isOk()).andReturn().getResponse().getContentAsString();
 
-        Long id = objectMapper.readValue(response, UserDto.class).getId();
+        String id = objectMapper.readValue(response, UserDto.class).getId();
 
         mockMvc.perform(delete("/users/{id}", id)
                         .contentType(MediaType.APPLICATION_JSON))
@@ -156,7 +156,7 @@ class UserControllerTest {
                         .contentType(MediaType.APPLICATION_JSON))
                 .andExpect(status().isOk()).andReturn().getResponse().getContentAsString();
 
-        Long id = objectMapper.readValue(response, UserDto.class).getId();
+        String id = objectMapper.readValue(response, UserDto.class).getId();
 
         var updatedUsername = "novak";
         var userToUpdate = new UserCreateDto(
@@ -195,7 +195,7 @@ class UserControllerTest {
                         .contentType(MediaType.APPLICATION_JSON))
                 .andExpect(status().isOk()).andReturn().getResponse().getContentAsString();
 
-        Long id = objectMapper.readValue(response, UserDto.class).getId();
+        String id = objectMapper.readValue(response, UserDto.class).getId();
 
         mockMvc.perform(post("/users/logout/{id}", id))
                 .andExpect(status().isOk());