diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/board/sevice/PostServiceImpl.java b/backEnd/src/main/java/com/quiz/ourclass/domain/board/sevice/PostServiceImpl.java
index d08a3037..ede3adb3 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/board/sevice/PostServiceImpl.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/board/sevice/PostServiceImpl.java
@@ -34,6 +34,7 @@
 import com.quiz.ourclass.global.util.UserAccessUtil;
 import java.time.LocalDateTime;
 import java.util.List;
+import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.log4j.Log4j2;
 import org.springframework.stereotype.Service;
@@ -201,8 +202,11 @@ public Boolean postDelete(Long postId) {
             }
         } else if (requesterRole == Role.TEACHER) {
             Long orgId = post.getOrganization().getId();
-            userAccessUtil.isOrganizationManager(member, orgId)
-                .orElseThrow(() -> new GlobalException(ErrorCode.MEMBER_NOT_IN_ORGANIZATION));
+            Optional<Organization> organization =
+                userAccessUtil.isOrganizationManager(member, orgId);
+            if (organization.isEmpty()) {
+                throw new GlobalException(ErrorCode.MEMBER_NOT_IN_ORGANIZATION);
+            }
         }
         commentRepository.deleteByPostId(post.getId());
         postRepository.delete(post);
@@ -237,8 +241,11 @@ public Boolean postReport(Long postId) {
         Post post = postRepository.findById(postId)
             .orElseThrow(() -> new GlobalException(ErrorCode.POST_NOT_FOUND));
 
-        userAccessUtil.isMemberOfOrganization(member, post.getOrganization().getId())
-            .orElseThrow(() -> new GlobalException(ErrorCode.MEMBER_NOT_IN_ORGANIZATION));
+        Optional<MemberOrganization> memberOrganization =
+            userAccessUtil.isMemberOfOrganization(member, post.getOrganization().getId());
+        if (memberOrganization.isEmpty()) {
+            throw new GlobalException(ErrorCode.MEMBER_NOT_IN_ORGANIZATION);
+        }
 
         String reportMember = member.getName();
         String authorMember = post.getAuthor().getName();
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatController.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatController.java
index 1e894255..e845209e 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatController.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatController.java
@@ -39,7 +39,8 @@ public void exitChatRoom(@PathVariable(value = "id") Long id) {
     }
 
     @GetMapping
-    public ResponseEntity<ResultResponse<?>> chatListView(MessageSliceRequest request) {
+    public ResponseEntity<ResultResponse<MessageResponse>> chatListView(
+        MessageSliceRequest request) {
         MessageResponse messageResponse = chatService.chatListView(request);
         return ResponseEntity.ok(ResultResponse.success(messageResponse));
     }
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatControllerDocs.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatControllerDocs.java
index e58c1f75..463864ff 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatControllerDocs.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatControllerDocs.java
@@ -52,7 +52,7 @@ void exitChatRoom(
         }
     )
     @GetMapping
-    ResponseEntity<ResultResponse<?>> chatListView(
+    ResponseEntity<ResultResponse<MessageResponse>> chatListView(
         MessageSliceRequest request
     );
 }
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterController.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterController.java
index 4363ffce..16970793 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterController.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterController.java
@@ -24,7 +24,7 @@ public class ChatFilterController implements ChatFilterControllerDocs {
     private final ChatFilterService chatFilterService;
 
     @PostMapping("/{organizationId}")
-    public ResponseEntity<ResultResponse<?>> register(
+    public ResponseEntity<ResultResponse<Long>> register(
         @PathVariable(value = "organizationId") Long organizationId,
         @RequestBody ChatFilterRequest request
     ) {
@@ -33,7 +33,7 @@ public ResponseEntity<ResultResponse<?>> register(
     }
 
     @PatchMapping("/{organizationId}/{id}")
-    public ResponseEntity<ResultResponse<?>> modify(
+    public ResponseEntity<ResultResponse<Boolean>> modify(
         @PathVariable(value = "organizationId") Long organizationId,
         @PathVariable(value = "id") Long id,
         @RequestBody ChatFilterRequest request
@@ -43,7 +43,7 @@ public ResponseEntity<ResultResponse<?>> modify(
     }
 
     @DeleteMapping("/{id}")
-    public ResponseEntity<ResultResponse<?>> delete(
+    public ResponseEntity<ResultResponse<Boolean>> delete(
         @PathVariable(value = "id") Long id
     ) {
         Boolean isDelete = chatFilterService.delete(id);
@@ -51,7 +51,7 @@ public ResponseEntity<ResultResponse<?>> delete(
     }
 
     @GetMapping
-    public ResponseEntity<ResultResponse<?>> select(
+    public ResponseEntity<ResultResponse<ChatFilterResponse>> select(
         ChatFilterSliceRequest request
     ) {
         ChatFilterResponse response = chatFilterService.select(request);
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterControllerDocs.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterControllerDocs.java
index 4a27890c..24afbda6 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterControllerDocs.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/controller/ChatFilterControllerDocs.java
@@ -34,7 +34,7 @@ public interface ChatFilterControllerDocs {
         }
     )
     @PostMapping("/{organizationId}")
-    ResponseEntity<ResultResponse<?>> register(
+    ResponseEntity<ResultResponse<Long>> register(
         @Parameter(name = "organizationId", description = "단체 ID 값", required = true, in = ParameterIn.PATH)
         @PathVariable(value = "organizationId") Long organizationId,
         @Parameter(name = "request", description = "필터링 단어 DTO", required = true, in = ParameterIn.DEFAULT)
@@ -57,7 +57,7 @@ ResponseEntity<ResultResponse<?>> register(
         }
     )
     @PatchMapping("/{organizationId}/{id}")
-    ResponseEntity<ResultResponse<?>> modify(
+    ResponseEntity<ResultResponse<Boolean>> modify(
         @Parameter(name = "organizationId", description = "단체 ID", required = true, in = ParameterIn.PATH)
         @PathVariable(value = "organizationId") Long organizationId,
         @Parameter(name = "id", description = "단어 필터링 ID 값", required = true, in = ParameterIn.PATH)
@@ -77,7 +77,7 @@ ResponseEntity<ResultResponse<?>> modify(
         }
     )
     @DeleteMapping("/{id}")
-    ResponseEntity<ResultResponse<?>> delete(
+    ResponseEntity<ResultResponse<Boolean>> delete(
         @Parameter(name = "id", description = "단어 필터링 ID 값", required = true, in = ParameterIn.PATH)
         @PathVariable(value = "id") Long chatFilterId
     );
@@ -96,7 +96,7 @@ ResponseEntity<ResultResponse<?>> delete(
         }
     )
     @GetMapping
-    ResponseEntity<ResultResponse<?>> select(
+    ResponseEntity<ResultResponse<ChatFilterResponse>> select(
         ChatFilterSliceRequest request
     );
 }
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/interceptor/ChatHandler.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/interceptor/ChatHandler.java
index 9e807834..c948e0d8 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/interceptor/ChatHandler.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/interceptor/ChatHandler.java
@@ -48,10 +48,10 @@ private void handleMessage(
                 }
                 connectToChatRoom(accessor, memberId);
                 break;
-            case SUBSCRIBE:
-            case SEND:
+            case SUBSCRIBE, SEND:
                 verifyAccessToken(getAccessToken(accessor));
                 break;
+            default:
         }
     }
 
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/mapper/ChatFilterMapper.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/mapper/ChatFilterMapper.java
index fb616e12..37b3c649 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/mapper/ChatFilterMapper.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/mapper/ChatFilterMapper.java
@@ -15,7 +15,7 @@
 public interface ChatFilterMapper {
 
     @Mapping(target = "id", ignore = true)
-    ChatFilter RequestToChatFilter(Organization organization, String badWord);
+    ChatFilter requestToChatFilter(Organization organization, String badWord);
 
     ChatFilter updateChatFilterFromRequest(
         ChatFilterRequest request,
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatFilterServiceImpl.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatFilterServiceImpl.java
index ae0888fe..0f030084 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatFilterServiceImpl.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatFilterServiceImpl.java
@@ -34,7 +34,7 @@ public Long register(Long organizationId, ChatFilterRequest request) {
         duplicateWordCheck(organization, request.badWord());
 
         return chatFilterRepository.save(
-            chatFilterMapper.RequestToChatFilter(organization, request.badWord())
+            chatFilterMapper.requestToChatFilter(organization, request.badWord())
         ).getId();
     }
 
diff --git a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatRoomServiceImpl.java b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatRoomServiceImpl.java
index f1b75e98..20bcbceb 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatRoomServiceImpl.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/domain/chat/service/ChatRoomServiceImpl.java
@@ -11,6 +11,7 @@
 import com.quiz.ourclass.global.exception.GlobalException;
 import com.quiz.ourclass.global.util.RedisUtil;
 import com.quiz.ourclass.global.util.UserAccessUtil;
+import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
@@ -60,8 +61,11 @@ public void isMemberAuthorizedToJoinRoom(Long memberId, Long chatRoomId) {
                 throw new GlobalException(ErrorCode.MEMBER_NOT_IN_ORGANIZATION);
             }
         } else if (member.getRole() == Role.TEACHER) {
-            userAccessUtil.isOrganizationManager(member, chatRoomId)
-                .orElseThrow(() -> new GlobalException(ErrorCode.MEMBER_NOT_IN_ORGANIZATION));
+            Optional<Organization> organization =
+                userAccessUtil.isOrganizationManager(member, chatRoomId);
+            if (organization.isEmpty()) {
+                throw new GlobalException(ErrorCode.MEMBER_NOT_IN_ORGANIZATION);
+            }
         }
     }
 }
diff --git a/backEnd/src/main/java/com/quiz/ourclass/global/config/SwaggerConfig.java b/backEnd/src/main/java/com/quiz/ourclass/global/config/SwaggerConfig.java
index 9c33ec47..51ff4743 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/global/config/SwaggerConfig.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/global/config/SwaggerConfig.java
@@ -1,5 +1,6 @@
 package com.quiz.ourclass.global.config;
 
+import com.quiz.ourclass.global.util.ConstantUtil;
 import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.info.Info;
@@ -15,37 +16,13 @@
 public class SwaggerConfig {
 
     @Bean
-    public GroupedOpenApi Api() {
+    public GroupedOpenApi api() {
         return GroupedOpenApi.builder()
             .group("all-api")
             .pathsToMatch("/**")
             .build();
     }
 
-    @Bean
-    public GroupedOpenApi memberApi() {
-        return GroupedOpenApi.builder()
-            .group("member-api")
-            .pathsToMatch("/members/**")
-            .build();
-    }
-
-    @Bean
-    public GroupedOpenApi boardApi() {
-        return GroupedOpenApi.builder()
-            .group("board-api")
-            .pathsToMatch("/board/**")
-            .build();
-    }
-
-    @Bean
-    public GroupedOpenApi ChallengeApi() {
-        return GroupedOpenApi.builder()
-            .group("challenge-api")
-            .pathsToMatch("/challenge/**")
-            .build();
-    }
-
     @Bean
     public OpenAPI openAPI() {
         Info info = new Info()
@@ -56,16 +33,16 @@ public OpenAPI openAPI() {
         SecurityScheme bearer = new SecurityScheme()
             .type(SecurityScheme.Type.HTTP)
             .scheme("bearer")
-            .bearerFormat("Authorization")
+            .bearerFormat(ConstantUtil.AUTHORIZATION)
             .in(SecurityScheme.In.HEADER)
             .name(HttpHeaders.AUTHORIZATION);
 
         // Security 요청 설정
         SecurityRequirement addSecurityItem = new SecurityRequirement();
-        addSecurityItem.addList("Authorization");
+        addSecurityItem.addList(ConstantUtil.AUTHORIZATION);
 
         Components components = new Components()
-            .addSecuritySchemes("Authorization", bearer);
+            .addSecuritySchemes(ConstantUtil.AUTHORIZATION, bearer);
 
         return new OpenAPI()
             .components(components)
diff --git a/backEnd/src/main/java/com/quiz/ourclass/global/util/ConstantUtil.java b/backEnd/src/main/java/com/quiz/ourclass/global/util/ConstantUtil.java
index 7a0a439d..87f4a5a1 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/global/util/ConstantUtil.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/global/util/ConstantUtil.java
@@ -6,7 +6,6 @@ public abstract class ConstantUtil {
     public static final String REDIS_ORG_KEY = "ORGANIZATION:";
     public static final int REDIS_ORG_ALIVE_MINUTE = 10;
     public static final String REDIS_CHAT_ROOM_KEY = "chatRoom:";
-    public static final String MONGO_DB_NAME = "chat";
     public static final long HOME_FRIEND_COUNT = 3L;
     public static final String BLACKLIST_ACCESS_TOKEN = "AT:";
     public static final String QUIZ_GAME = "quiz:";
@@ -14,11 +13,15 @@ public abstract class ConstantUtil {
     public static final int RELAY_REWARD = 50;
     public static final Long RELAY_TIMEOUT_DAY = 1L;
     public static final String FCM_KEY_PREFIX = "FCM_";
-    public static final int MAX_RETRIES = 5; //최대 재시도 횟수
-    public static final long INITIAL_BACKOFF = 1000L; //초기 백오프 시간 (1초)
     public static final String QUIZ_GAMER = "gamer";
     public static final String QUIZ_QUESTION = "question";
     public static final String RANKING = "ranking";
     public static final String QUIZ_ANSWER = "answer";
+    public static final String AUTHORIZATION = "Authorization";
 
+    // 인스턴스화 방지
+    private ConstantUtil() {
+        throw new UnsupportedOperationException(
+            "This is a utility class and cannot be instantiated");
+    }
 }
diff --git a/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmType.java b/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmType.java
index 4bd95d3e..8810bfb5 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmType.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmType.java
@@ -12,5 +12,5 @@ public enum FcmType {
     CHALLENGE("함께달리기"),
     RELAY("이어달리기"),
     ;
-    private final String Type;
+    private final String type;
 }
diff --git a/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmUtil.java b/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmUtil.java
index abb0c172..d7aca043 100644
--- a/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmUtil.java
+++ b/backEnd/src/main/java/com/quiz/ourclass/global/util/FcmUtil.java
@@ -58,33 +58,6 @@ public void sendMessage(Message message) {
         } catch (FirebaseMessagingException e) {
             log.error("fcm send error");
         }
-//        int attempt = 0;
-//        long backoff = ConstantUtil.INITIAL_BACKOFF;
-//
-//        while (attempt < ConstantUtil.MAX_RETRIES) { //지수 백오프 전략
-//            try {
-//                FirebaseMessaging.getInstance().send(message);
-//                log.info("FCM Send Success");
-//                break;  // 성공 시 루프 종료
-//            } catch (FirebaseMessagingException e) {
-//                log.error("FCM Send Error: {}", e.getMessage());
-//                attempt++;
-//                if (attempt >= ConstantUtil.MAX_RETRIES) {
-//                    // 최대 재시도 횟수 도달 시 루프 종료
-//                    // 다른 메시지 시스템으로 알림을 전송하는 방법을 고려해볼 수 있음
-//                    log.error("Reached Maximum Retry Attempts");
-//                    break;
-//                }
-//                try {
-//                    Thread.sleep(backoff);  // 지수 백오프를 위한 대기
-//                } catch (InterruptedException ie) {
-//                    Thread.currentThread().interrupt();
-//                    log.error("Interrupted While Waiting For Retry");
-//                    break;  // 인터럽트 발생 시 루프 종료
-//                }
-//                backoff *= 2;
-//            }
-//        }
     }
 
     public FcmDTO makeFcmDTO(String title, String body) {
diff --git a/backEnd/src/test/java/com/quiz/ourclass/OurClassApplicationTests.java b/backEnd/src/test/java/com/quiz/ourclass/OurClassApplicationTests.java
index e4528293..9dbdeb05 100644
--- a/backEnd/src/test/java/com/quiz/ourclass/OurClassApplicationTests.java
+++ b/backEnd/src/test/java/com/quiz/ourclass/OurClassApplicationTests.java
@@ -1,13 +1,8 @@
 package com.quiz.ourclass;
 
-import org.junit.jupiter.api.Test;
 import org.springframework.boot.test.context.SpringBootTest;
 
 @SpringBootTest(classes = OurClassApplicationTests.class)
 class OurClassApplicationTests {
 
-    @Test
-    void contextLoads() {
-    }
-
 }