diff --git a/src/auth/auth.service.ts b/src/auth/auth.service.ts
index 5db8160..276feff 100644
--- a/src/auth/auth.service.ts
+++ b/src/auth/auth.service.ts
@@ -8,11 +8,8 @@ import {
 } from '@nestjs/common';
 import { Cache } from 'cache-manager';
 import { v4 as uuidv4 } from 'uuid';
-import axios from 'axios';
-import * as CryptoJS from 'crypto-js';
 
 import { MailService } from '../mail/mail.service';
-import { User } from '../users/entities/user.entity';
 import {
   refreshTokenExpirationInCache,
   refreshTokenExpirationInCacheShortVersion,
@@ -28,12 +25,8 @@ import { sendPasswordResetEmailOutput } from './dtos/send-password-reset-email.d
 import { RefreshTokenDto, RefreshTokenOutput } from './dtos/token.dto';
 import { ValidateUserDto, ValidateUserOutput } from './dtos/validate-user.dto';
 import { ONEYEAR, Payload } from './jwt/jwt.payload';
-import { KakaoAuthorizeOutput, LoginWithKakaoDto } from './dtos/kakao.dto';
-import { googleUserInfo } from './dtos/google.dto';
 import { customJwtService } from './jwt/jwt.service';
 import { UserRepository } from '../users/repository/user.repository';
-import { CategoryRepository } from '../categories/category.repository';
-import { OAuthUtil } from './util/oauth.util';
 
 @Injectable()
 export class AuthService {
diff --git a/src/contents/contents.controller.ts b/src/contents/contents.controller.ts
index 36b56d5..a40a2e4 100644
--- a/src/contents/contents.controller.ts
+++ b/src/contents/contents.controller.ts
@@ -87,17 +87,11 @@ export class ContentsController {
     type: ErrorOutput,
   })
   @Post('multiple')
-  @UseInterceptors(TransactionInterceptor)
   async addMultipleContents(
     @AuthUser() user: User,
     @Body() contentLinks: AddMultipleContentsBodyDto,
-    @TransactionManager() queryRunnerManager: EntityManager,
   ): Promise<AddContentOutput> {
-    return this.contentsService.addMultipleContents(
-      user,
-      contentLinks,
-      queryRunnerManager,
-    );
+    return this.contentsService.addMultipleContents(user, contentLinks);
   }
 
   @ApiOperation({
@@ -117,17 +111,11 @@ export class ContentsController {
     type: ErrorOutput,
   })
   @Patch()
-  @UseInterceptors(TransactionInterceptor)
   async updateContent(
     @AuthUser() user: User,
     @Body() content: UpdateContentBodyDto,
-    @TransactionManager() queryRunnerManager: EntityManager,
   ): Promise<UpdateContentOutput> {
-    return this.contentsService.updateContent(
-      user,
-      content,
-      queryRunnerManager,
-    );
+    return this.contentsService.updateContent(user, content);
   }
 
   @ApiOperation({
@@ -143,17 +131,11 @@ export class ContentsController {
     type: ErrorOutput,
   })
   @Patch(':contentId/favorite')
-  @UseInterceptors(TransactionInterceptor)
   async toggleFavorite(
     @AuthUser() user: User,
-    @Param('contentId', new ParseIntPipe()) contentId: number,
-    @TransactionManager() queryRunnerManager: EntityManager,
+    @Param('contentId', ParseIntPipe) contentId: number,
   ): Promise<toggleFavoriteOutput> {
-    return this.contentsService.toggleFavorite(
-      user,
-      contentId,
-      queryRunnerManager,
-    );
+    return this.contentsService.toggleFavorite(user, contentId);
   }
 
   @ApiOperation({
@@ -169,17 +151,11 @@ export class ContentsController {
     type: ErrorOutput,
   })
   @Delete(':contentId')
-  @UseInterceptors(TransactionInterceptor)
   async deleteContent(
     @AuthUser() user: User,
     @Param('contentId', new ParseIntPipe()) contentId: number,
-    @TransactionManager() queryRunnerManager: EntityManager,
   ): Promise<DeleteContentOutput> {
-    return this.contentsService.deleteContent(
-      user,
-      contentId,
-      queryRunnerManager,
-    );
+    return this.contentsService.deleteContent(user, contentId);
   }
 
   @ApiOperation({
diff --git a/src/contents/contents.service.ts b/src/contents/contents.service.ts
index cdefe77..f534ac1 100644
--- a/src/contents/contents.service.ts
+++ b/src/contents/contents.service.ts
@@ -31,6 +31,7 @@ import { CategoryRepository } from '../categories/category.repository';
 import { getLinkInfo } from './util/content.util';
 import { GetLinkInfoResponseDto } from './dtos/get-link.response.dto';
 import { checkContentDuplicateAndAddCategorySaveLog } from '../categories/utils/category.util';
+import { Transactional } from '../common/aop/transactional';
 
 @Injectable()
 export class ContentsService {
@@ -116,10 +117,11 @@ export class ContentsService {
     }
   }
 
+  @Transactional()
   async addMultipleContents(
     user: User,
     { contentLinks, categoryName, parentId }: AddMultipleContentsBodyDto,
-    queryRunnerManager: EntityManager,
+    entityManager?: EntityManager,
   ): Promise<AddContentOutput> {
     try {
       const userInDb =
@@ -136,7 +138,7 @@ export class ContentsService {
             categoryName,
             parentId,
             userInDb,
-            queryRunnerManager,
+            entityManager!,
           );
         }
         for (const link of contentLinks) {
@@ -152,7 +154,7 @@ export class ContentsService {
             );
           }
 
-          const newContent = queryRunnerManager.create(Content, {
+          const newContent = entityManager!.create(Content, {
             link,
             title,
             siteName,
@@ -161,10 +163,7 @@ export class ContentsService {
             description,
             user: userInDb,
           });
-          await queryRunnerManager.save(newContent);
-
-          // 각 링크마다 처리 후 transaction commit
-          await queryRunnerManager.query('COMMIT');
+          await this.contentRepository.saveOne(newContent, entityManager);
         }
       }
 
@@ -187,7 +186,7 @@ export class ContentsService {
       categoryName,
       parentId,
     }: UpdateContentBodyDto,
-    queryRunnerManager: EntityManager,
+    entityManager?: EntityManager,
   ): Promise<AddContentOutput> {
     const newContentObj = {
       link,
@@ -217,7 +216,7 @@ export class ContentsService {
           categoryName,
           parentId,
           userInDb,
-          queryRunnerManager,
+          entityManager!,
         );
 
         await checkContentDuplicateAndAddCategorySaveLog(
@@ -227,7 +226,7 @@ export class ContentsService {
         );
       }
 
-      await queryRunnerManager.save(Content, [
+      await entityManager!.save(Content, [
         { id: content.id, ...newContentObj, ...(category && { category }) },
       ]);
 
@@ -240,7 +239,7 @@ export class ContentsService {
   async toggleFavorite(
     user: User,
     contentId: number,
-    queryRunnerManager: EntityManager,
+    entityManager?: EntityManager,
   ): Promise<toggleFavoriteOutput> {
     try {
       const userInDb = await this.userRepository.findOneWithContents(user.id);
@@ -258,7 +257,7 @@ export class ContentsService {
       }
 
       content.favorite = !content.favorite;
-      await queryRunnerManager.save(content);
+      await entityManager!.save(content);
 
       return {};
     } catch (e) {
@@ -269,7 +268,7 @@ export class ContentsService {
   async deleteContent(
     user: User,
     contentId: number,
-    queryRunnerManager: EntityManager,
+    entityManager?: EntityManager,
   ): Promise<DeleteContentOutput> {
     try {
       const content = await this.contentRepository.findOneBy({ id: contentId });
@@ -284,7 +283,7 @@ export class ContentsService {
       }
 
       // delete content
-      await queryRunnerManager.delete(Content, content.id);
+      await entityManager!.delete(Content, content.id);
 
       return {};
     } catch (e) {
diff --git a/src/contents/repository/content.repository.ts b/src/contents/repository/content.repository.ts
index daf4ee4..1085624 100644
--- a/src/contents/repository/content.repository.ts
+++ b/src/contents/repository/content.repository.ts
@@ -1,4 +1,4 @@
-import { DataSource, Repository } from 'typeorm';
+import { DataSource, EntityManager, Repository } from 'typeorm';
 import { Content } from '../entities/content.entity';
 import { Injectable } from '@nestjs/common';
 
@@ -43,4 +43,11 @@ export class ContentRepository extends Repository<Content> {
       .andWhere('content.reminder < :now', { now: new Date() })
       .getCount();
   }
+
+  async saveOne(
+    content: Content,
+    entityManager?: EntityManager,
+  ): Promise<Content> {
+    return entityManager ? entityManager.save(content) : this.save(content);
+  }
 }