diff --git a/src/main/java/com/ward/ward_server/api/item/controller/PublicItemController.java b/src/main/java/com/ward/ward_server/api/item/controller/PublicItemController.java
index 2a8f0be..cfa4564 100644
--- a/src/main/java/com/ward/ward_server/api/item/controller/PublicItemController.java
+++ b/src/main/java/com/ward/ward_server/api/item/controller/PublicItemController.java
@@ -25,6 +25,10 @@
 @RequestMapping("/public/items")
 public class PublicItemController {
 
+    private static final int TOP_LIMIT_10 = 10;
+    private static final int TOP_LIMIT_50 = 50;
+    private static final List<Integer> ALLOWED_LIMITS = List.of(TOP_LIMIT_10, TOP_LIMIT_50);
+
     private final ItemService itemService;
 
     @GetMapping("/{itemId}/details")
@@ -51,8 +55,8 @@ public ApiResponse<PageResponse<ItemSimpleResponse>> getItemPage(@Authentication
     @GetMapping("/top")
     public ApiResponse<List<ItemTopRankResponse>> getTopItemsByCategory(@RequestParam("category") Category category,
                                                                         @RequestParam("limit") int limit) {
-        if (limit != 10 && limit != 50) {
-            throw new ApiException(ExceptionCode.INVALID_INPUT, "Limit 는 10 or 50 이어야합니다.");
+        if (!ALLOWED_LIMITS.contains(limit)) {
+            throw new ApiException(ExceptionCode.INVALID_INPUT, "Limit는 10 또는 50이어야 합니다.");
         }
 
         List<ItemTopRankResponse> topItemsResponse = itemService.getTopItemsResponseByCategory(category, limit);
diff --git a/src/main/java/com/ward/ward_server/api/item/scheduler/ItemViewCountScheduler.java b/src/main/java/com/ward/ward_server/api/item/scheduler/ItemViewCountScheduler.java
index c2c8e42..e63a1b7 100644
--- a/src/main/java/com/ward/ward_server/api/item/scheduler/ItemViewCountScheduler.java
+++ b/src/main/java/com/ward/ward_server/api/item/scheduler/ItemViewCountScheduler.java
@@ -20,6 +20,8 @@
 @RequiredArgsConstructor
 public class ItemViewCountScheduler {
 
+    private static final int ONE_DAY = 1;
+
     private final ItemViewCountRepository itemViewCountRepository;
     private final ItemTopRankRepository itemTopRankRepository;
 
@@ -32,7 +34,7 @@ public void updateViewCounts() {
     @Transactional
     public void executeUpdateViewCounts() {
         LocalDateTime now = LocalDateTime.now();
-        LocalDateTime startTime = now.minusDays(1);
+        LocalDateTime startTime = now.minusDays(ONE_DAY);
 
         List<ItemViewCount> viewCounts = itemViewCountRepository.findViewCountsBetween(startTime, now);
 
@@ -48,7 +50,7 @@ public void executeUpdateViewCounts() {
 
         // 새로운 순위 데이터를 삽입
         categoryItemViewCounts.forEach((category, itemViewCounts) -> {
-            int rank = 1;
+            int rank = ONE_DAY;
             for (Map.Entry<Item, Long> entry : itemViewCounts.entrySet()) {
                 ItemTopRank itemTopRank = ItemTopRank.builder()
                         .item(entry.getKey())
diff --git a/src/main/java/com/ward/ward_server/api/item/service/BrandService.java b/src/main/java/com/ward/ward_server/api/item/service/BrandService.java
index db98391..fdf2f14 100644
--- a/src/main/java/com/ward/ward_server/api/item/service/BrandService.java
+++ b/src/main/java/com/ward/ward_server/api/item/service/BrandService.java
@@ -30,6 +30,7 @@
 
 @Service
 @RequiredArgsConstructor
+@Transactional(readOnly = true)
 public class BrandService {
     private final BrandRepository brandRepository;
     private final ItemRepository itemRepository;
@@ -52,13 +53,11 @@ public BrandResponse createBrand(String koreanName, String englishName, String b
         return getBrandResponse(savedBrand);
     }
 
-    @Transactional(readOnly = true)
     public PageResponse<BrandInfoResponse> getBrandAndItem3Page(BasicSort sort, int page) {
         Page<BrandInfoResponse> brandInfoPage = brandRepository.getBrandAndItem3Page(sort, PageRequest.of(page, API_PAGE_SIZE));
         return new PageResponse<>(brandInfoPage.getContent(), brandInfoPage);
     }
 
-    @Transactional(readOnly = true)
     public List<BrandRecommendedResponse> getRecommendedBrands() {
         return brandRepository.findTop10ByOrderByViewCountDesc()
                 .stream()
@@ -66,13 +65,11 @@ public List<BrandRecommendedResponse> getRecommendedBrands() {
                 .collect(Collectors.toList());
     }
 
-    @Transactional(readOnly = true)
     public PageResponse<BrandItemResponse> getBrandItemPage(long brandId, BasicSort sort, int page) {
         Page<BrandItemResponse> brandInfoPage = itemRepository.getBrandItemPage(brandId, sort, PageRequest.of(page, API_PAGE_SIZE));
         return new PageResponse<>(brandInfoPage.getContent(), brandInfoPage);
     }
 
-    @Transactional(readOnly = true)
     public PageResponse<ReleaseInfoSimpleResponse> getBrandReleaseInfoPage(long brandId, int page) {
         Page<ReleaseInfoSimpleResponse> releaseInfoInfoPage = releaseInfoRepository.getBrandReleaseInfoPage(brandId, PageRequest.of(page, API_PAGE_SIZE));
         return new PageResponse<>(releaseInfoInfoPage.getContent(), releaseInfoInfoPage);
diff --git a/src/main/java/com/ward/ward_server/api/item/service/ItemService.java b/src/main/java/com/ward/ward_server/api/item/service/ItemService.java
index bb4c661..eb5c05c 100644
--- a/src/main/java/com/ward/ward_server/api/item/service/ItemService.java
+++ b/src/main/java/com/ward/ward_server/api/item/service/ItemService.java
@@ -31,6 +31,10 @@
 @Transactional(readOnly = true)
 @Slf4j
 public class ItemService {
+
+    private static final int FIRST_PAGE = 0;
+    private static final int HOURS_TO_SUBTRACT = 9;
+
     private final ItemRepository itemRepository;
     private final BrandRepository brandRepository;
     private final ItemImageRepository itemImageRepository;
@@ -89,34 +93,31 @@ public void increaseViewCount(Item item) {
                 .build());
     }
 
-    @Transactional(readOnly = true)
     public List<ItemSimpleResponse> getItem10List(Long userId, Section section, Category category) {
         return switch (section) {
             case DUE_TODAY, RELEASE_NOW, RELEASE_SCHEDULE ->
-                    itemRepository.getItem10List(userId, LocalDateTime.now().minusHours(9), category, section); //HACK DB 시간 설정 전까지는 -9시간으로 비교해야 한다.
+                    itemRepository.getItem10List(userId, LocalDateTime.now().minusHours(HOURS_TO_SUBTRACT), category, section); //HACK DB 시간 설정 전까지는 -9시간으로 비교해야 한다.
             default -> throw new ApiException(INVALID_INPUT, SECTION_NOT_AVAILABLE_THIS_PAGE.getMessage());
         };
     }
 
-    @Transactional(readOnly = true)
     public PageResponse<ItemSimpleResponse> getItemPage(Long userId, Section section, Category category, int page, String date) {
         log.info("하늘:{}", date);
         return switch (section) {
             case RELEASE_SCHEDULE, CLOSED -> {
-                Page<ItemSimpleResponse> itemPageInfo = itemRepository.getItemPage(userId, LocalDateTime.now().minusHours(9), category, section, date, PageRequest.of(page, API_PAGE_SIZE)); //HACK DB 시간 설정 전까지는 -9시간으로 비교해야 한다.
+                Page<ItemSimpleResponse> itemPageInfo = itemRepository.getItemPage(userId, LocalDateTime.now().minusHours(HOURS_TO_SUBTRACT), category, section, date, PageRequest.of(page, API_PAGE_SIZE)); //HACK DB 시간 설정 전까지는 -9시간으로 비교해야 한다.
                 yield new PageResponse<>(itemPageInfo.getContent(), itemPageInfo);
             }
             default -> throw new ApiException(INVALID_INPUT, SECTION_NOT_AVAILABLE_THIS_PAGE.getMessage());
         };
     }
 
-    @Transactional(readOnly = true)
     public List<ItemTopRankResponse> getTopItemsResponseByCategory(Category category, int limit) {
         List<ItemTopRank> topItems;
         if (category == Category.ALL) {
-            topItems = itemTopRankRepository.findTopItems(PageRequest.of(0, limit));
+            topItems = itemTopRankRepository.findTopItems(PageRequest.of(FIRST_PAGE, limit));
         } else {
-            topItems = itemTopRankRepository.findTopItemsByCategory(category, PageRequest.of(0, limit));
+            topItems = itemTopRankRepository.findTopItemsByCategory(category, PageRequest.of(FIRST_PAGE, limit));
         }
         return convertToTopResponse(topItems);
     }
diff --git a/src/main/java/com/ward/ward_server/api/item/webCrawler/KasinaWebCrawler.java b/src/main/java/com/ward/ward_server/api/item/webCrawler/KasinaWebCrawler.java
index 56cbfa0..8fc548c 100644
--- a/src/main/java/com/ward/ward_server/api/item/webCrawler/KasinaWebCrawler.java
+++ b/src/main/java/com/ward/ward_server/api/item/webCrawler/KasinaWebCrawler.java
@@ -1,6 +1,7 @@
 package com.ward.ward_server.api.item.webCrawler;
 
 import com.ward.ward_server.api.item.dto.WebProductData;
+import com.ward.ward_server.global.config.CrawlerConfig;
 import lombok.extern.slf4j.Slf4j;
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
@@ -27,8 +28,8 @@ public class KasinaWebCrawler {
     private WebDriver driver;
 
     @Autowired
-    public KasinaWebCrawler(CrawlerProperties crawlerProperties) {
-        String chromeDriverPath = crawlerProperties.getChromeDriverPath();
+    public KasinaWebCrawler(CrawlerConfig crawlerConfig) {
+        String chromeDriverPath = crawlerConfig.getChromeDriverPath();
         ChromeOptions chromeOptions = new ChromeOptions();
 //        chromeOptions.setBinary("/usr/bin/google-chrome"); // EC2 쓸 때 해제
         chromeOptions.addArguments("--headless"); //헤드리스 모드로 실행, 실제 창이 표시되지 않는다.
diff --git a/src/main/java/com/ward/ward_server/api/item/webCrawler/NikeWebCrawler.java b/src/main/java/com/ward/ward_server/api/item/webCrawler/NikeWebCrawler.java
index f9f7dcb..67f6890 100644
--- a/src/main/java/com/ward/ward_server/api/item/webCrawler/NikeWebCrawler.java
+++ b/src/main/java/com/ward/ward_server/api/item/webCrawler/NikeWebCrawler.java
@@ -1,6 +1,7 @@
 package com.ward.ward_server.api.item.webCrawler;
 
 import com.ward.ward_server.api.item.dto.WebProductData;
+import com.ward.ward_server.global.config.CrawlerConfig;
 import lombok.extern.slf4j.Slf4j;
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
@@ -24,8 +25,8 @@ public class NikeWebCrawler {
     private WebDriver driver;
 
     @Autowired
-    public NikeWebCrawler(CrawlerProperties crawlerProperties) {
-        String chromeDriverPath = crawlerProperties.getChromeDriverPath();
+    public NikeWebCrawler(CrawlerConfig crawlerConfig) {
+        String chromeDriverPath = crawlerConfig.getChromeDriverPath();
         ChromeOptions chromeOptions = new ChromeOptions();
 //        chromeOptions.setBinary("/usr/bin/google-chrome"); // EC2 쓸 때 해제
         chromeOptions.addArguments("--headless"); //헤드리스 모드로 실행, 실제 창이 표시되지 않는다.
diff --git a/src/main/java/com/ward/ward_server/api/releaseInfo/service/ReleaseInfoService.java b/src/main/java/com/ward/ward_server/api/releaseInfo/service/ReleaseInfoService.java
index 6560645..3814909 100644
--- a/src/main/java/com/ward/ward_server/api/releaseInfo/service/ReleaseInfoService.java
+++ b/src/main/java/com/ward/ward_server/api/releaseInfo/service/ReleaseInfoService.java
@@ -36,6 +36,7 @@
 
 @Service
 @RequiredArgsConstructor
+@Transactional(readOnly = true)
 public class ReleaseInfoService {
     private final ReleaseInfoRepository releaseInfoRepository;
     private final DrawPlatformRepository drawPlatformRepository;
@@ -70,13 +71,11 @@ public ReleaseInfoDetailResponse createReleaseInfo(Long itemId, String platformN
         return getDetailResponse(item.getBrand(), item, platform, savedReleaseInfo);
     }
 
-    @Transactional(readOnly = true)
     public ReleaseInfoDetailResponse getReleaseInfo(Long releaseInfoId) {
         ReleaseInfo releaseInfo = releaseInfoRepository.findById(releaseInfoId).orElseThrow(() -> new ApiException(RELEASE_INFO_NOT_FOUND));
         return getDetailResponse(releaseInfo.getItem().getBrand(), releaseInfo.getItem(), releaseInfo.getDrawPlatform(), releaseInfo);
     }
 
-    @Transactional(readOnly = true)
     public List<ReleaseInfoSimpleResponse> getReleaseInfo10List(Long userId, Section section, Category category) {
         return switch (section){
             case DUE_TODAY, RELEASE_WISH, REGISTER_TODAY -> releaseInfoRepository.getReleaseInfo10List(userId, LocalDateTime.now().minusHours(9), category, section); //HACK DB 시간 설정 전까지는 -9시간으로 비교해야 한다.
@@ -84,7 +83,6 @@ public List<ReleaseInfoSimpleResponse> getReleaseInfo10List(Long userId, Section
         };
     }
 
-    @Transactional(readOnly = true)
     public PageResponse<ReleaseInfoSimpleResponse> getReleaseInfoPage(Long userId, Section section, Category category, int page) {
         return switch (section){
             case DUE_TODAY, RELEASE_NOW, REGISTER_TODAY ->{
@@ -95,14 +93,12 @@ public PageResponse<ReleaseInfoSimpleResponse> getReleaseInfoPage(Long userId, S
         };
     }
 
-    @Transactional(readOnly = true)
     public Page<ReleaseInfo> getOngoingReleaseInfos(Long itemId, int page, int size) {
         Item item = itemRepository.findById(itemId).orElseThrow(() -> new ApiException(ITEM_NOT_FOUND));
         LocalDateTime now = LocalDateTime.now();
         return releaseInfoRepository.findByItemAndDueDateAfter(item, now, PageRequest.of(page, size));
     }
 
-    @Transactional(readOnly = true)
     public Page<ReleaseInfo> getCompletedReleaseInfos(Long itemId, int page, int size) {
         Item item = itemRepository.findById(itemId).orElseThrow(() -> new ApiException(ITEM_NOT_FOUND));
         LocalDateTime now = LocalDateTime.now();
@@ -196,7 +192,6 @@ private ReleaseInfoDetailResponse getDetailResponse(Brand brand, Item item, Draw
                 releaseInfo.getNotificationMethod().getDesc(), releaseInfo.getReleaseMethod().getDesc(), releaseInfo.getDeliveryMethod().getDesc());
     }
 
-    @Transactional(readOnly = true)
     public List<ExpiringItemResponse> getExpiringItems(int limit) {
         LocalDateTime now = LocalDateTime.now();
         Pageable pageable = PageRequest.of(0, limit);
diff --git a/src/main/java/com/ward/ward_server/api/user/controller/HelloController.java b/src/main/java/com/ward/ward_server/api/user/controller/HelloController.java
index 03db1da..5f50128 100644
--- a/src/main/java/com/ward/ward_server/api/user/controller/HelloController.java
+++ b/src/main/java/com/ward/ward_server/api/user/controller/HelloController.java
@@ -19,14 +19,14 @@ public ApiResponse greeting(){
 
     @GetMapping("/user/secured")
     public ApiResponse secured(@AuthenticationPrincipal CustomUserDetails principal) {
-        String secured = "If you see this, then you're logged in as user " + principal.getEmail()
+        String secured = "User 권한으로 접근 성공 - " + principal.getEmail()
                 + " User ID: " + principal.getUserId();
         return ApiResponse.ok(secured);
     }
 
     @GetMapping("/admin")
     public ApiResponse admin(@AuthenticationPrincipal CustomUserDetails principal) {
-        String admin = "If you see this, then you are an Admin. User ID: " + principal.getUserId();
+        String admin = "Admin 권한으로 접근 성공 - " + principal.getUserId();
         return ApiResponse.ok(admin);
     }
 }
diff --git a/src/main/java/com/ward/ward_server/api/user/dto/AddSocialLoginRequest.java b/src/main/java/com/ward/ward_server/api/user/dto/AddSocialLoginRequest.java
index c186cdd..d0c9243 100644
--- a/src/main/java/com/ward/ward_server/api/user/dto/AddSocialLoginRequest.java
+++ b/src/main/java/com/ward/ward_server/api/user/dto/AddSocialLoginRequest.java
@@ -4,8 +4,8 @@
 import jakarta.validation.constraints.NotBlank;
 
 public record AddSocialLoginRequest(
-        @NotBlank(message = "Provider cannot be empty") String provider,
-        @NotBlank(message = "Provider ID cannot be empty") String providerId,
-        @Email(message = "Email should be valid") String email,
+        @NotBlank(message = "provider는 필수 항목입니다.") String provider,
+        @NotBlank(message = "providerId는 필수 항목입니다.") String providerId,
+        @Email(message = "유효한 이메일 주소를 입력해 주세요.") String email,
         String appleRefreshToken
 ) {}
diff --git a/src/main/java/com/ward/ward_server/api/user/dto/LoginRequest.java b/src/main/java/com/ward/ward_server/api/user/dto/LoginRequest.java
index 18309bb..1d52de2 100644
--- a/src/main/java/com/ward/ward_server/api/user/dto/LoginRequest.java
+++ b/src/main/java/com/ward/ward_server/api/user/dto/LoginRequest.java
@@ -4,7 +4,7 @@
 import jakarta.validation.constraints.NotBlank;
 
 public record LoginRequest(
-        @NotBlank(message = "Provider cannot be empty") String provider,
-        @NotBlank(message = "Provider ID cannot be empty") String providerId,
-        @Email(message = "Email should be valid") String email
+        @NotBlank(message = "provider는 필수 항목입니다.") String provider,
+        @NotBlank(message = "providerId는 필수 항목입니다.") String providerId,
+        @Email(message = "유효한 이메일 주소를 입력해 주세요.") String email
 ) {}
diff --git a/src/main/java/com/ward/ward_server/api/user/dto/RegisterRequest.java b/src/main/java/com/ward/ward_server/api/user/dto/RegisterRequest.java
index d8b58d0..50a722c 100644
--- a/src/main/java/com/ward/ward_server/api/user/dto/RegisterRequest.java
+++ b/src/main/java/com/ward/ward_server/api/user/dto/RegisterRequest.java
@@ -4,13 +4,19 @@
 import jakarta.validation.constraints.NotBlank;
 
 public record RegisterRequest(
-        @NotBlank(message = "Provider cannot be empty") String provider,
-        @NotBlank(message = "Provider ID cannot be empty") String providerId,
-        @NotBlank(message = "Name cannot be empty") String name,
-        @Email(message = "Email should be valid") String email,
+        @NotBlank(message = "provider는 필수 항목입니다.") String provider,
+        @NotBlank(message = "providerId는 필수 항목입니다.") String providerId,
+        @NotBlank(message = "이름은 필수 항목입니다.") String name,
+        @Email(message = "유효한 이메일 주소를 입력해 주세요.") String email,
         String appleRefreshToken,
-        @NotBlank(message = "Nickname cannot be empty") String nickname,
+        @NotBlank(message = "닉네임은 필수 항목입니다.") String nickname,
         Boolean emailNotification,
         Boolean appPushNotification,
         Boolean snsNotification
-) {}
+) {
+    public RegisterRequest {
+        if (emailNotification == null) emailNotification = false;
+        if (appPushNotification == null) appPushNotification = false;
+        if (snsNotification == null) snsNotification = false;
+    }
+}
diff --git a/src/main/java/com/ward/ward_server/api/user/dto/UserInfoUpdateRequest.java b/src/main/java/com/ward/ward_server/api/user/dto/UserInfoUpdateRequest.java
index f45d617..c83f831 100644
--- a/src/main/java/com/ward/ward_server/api/user/dto/UserInfoUpdateRequest.java
+++ b/src/main/java/com/ward/ward_server/api/user/dto/UserInfoUpdateRequest.java
@@ -4,8 +4,8 @@
 import jakarta.validation.constraints.NotBlank;
 
 public record UserInfoUpdateRequest(
-        @NotBlank(message = "Provider cannot be empty") String provider,
-        @NotBlank(message = "Provider ID cannot be empty") String providerId,
-        @Email(message = "Email should be valid") String oldEmail,
-        @Email(message = "Email should be valid") String newEmail
+        @NotBlank(message = "provider는 필수 항목입니다.") String provider,
+        @NotBlank(message = "providerId는 필수 항목입니다.") String providerId,
+        @Email(message = "유효한 이전 이메일 주소를 입력해 주세요.") String oldEmail,
+        @Email(message = "유효한 새 이메일 주소를 입력해 주세요.") String newEmail
 ) {}
diff --git a/src/main/java/com/ward/ward_server/api/user/service/AppleUserService.java b/src/main/java/com/ward/ward_server/api/user/service/AppleUserService.java
index a093494..50be3a9 100644
--- a/src/main/java/com/ward/ward_server/api/user/service/AppleUserService.java
+++ b/src/main/java/com/ward/ward_server/api/user/service/AppleUserService.java
@@ -9,8 +9,6 @@
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
-import java.util.Optional;
-
 @Service
 @RequiredArgsConstructor
 @Slf4j
@@ -19,43 +17,19 @@ public class AppleUserService {
 
     private final SocialLoginRepository socialLoginRepository;
 
-//    @Transactional
-//    public void updateUserInfo(String provider, String providerId, String oldEmail, String newEmail) {
-//        // SocialLogin 테이블에서 사용자 정보를 찾습니다.
-//        Optional<SocialLogin> optionalSocialLogin = socialLoginRepository.findByProviderAndProviderIdAndEmail(provider, providerId, oldEmail);
-//
-//        if (optionalSocialLogin.isPresent()) {
-//            // SocialLogin 정보를 통해 사용자 정보를 가져옵니다.
-//            SocialLogin socialLogin = optionalSocialLogin.get();
-//            User user = socialLogin.getUser();
-//
-//            // 사용자 이메일 업데이트
-//            user.updateEmail(newEmail);
-//            log.info("사용자 정보 업데이트: {}", user);
-//
-//            // 소셜 로그인 정보 이메일 업데이트
-//            socialLogin.updateEmail(newEmail);
-//            log.info("소셜 로그인 정보 업데이트: {}", socialLogin);
-//        } else {
-//            // SocialLogin 정보가 존재하지 않으면 로깅하여 알립니다.
-//            log.warn("해당 이메일을 가진 사용자를 찾을 수 없습니다: {}", oldEmail);
-//        }
-//    }
     @Transactional
     public void updateUserInfo(String provider, String providerId, String oldEmail, String newEmail) {
-        // SocialLogin 테이블에서 사용자 정보를 찾습니다.
-        Optional<SocialLogin> optionalSocialLogin = socialLoginRepository.findByProviderAndProviderIdAndEmail(provider, providerId, oldEmail);
-
-        if (optionalSocialLogin.isPresent()) {
-            // SocialLogin 정보를 통해 사용자 정보를 가져옵니다.
-            SocialLogin socialLogin = optionalSocialLogin.get();
-            socialLogin.updateEmail(newEmail);
+        // SocialLogin 테이블에서 사용자 정보를 찾고, 없으면 예외를 던집니다.
+        SocialLogin socialLogin = socialLoginRepository
+                .findByProviderAndProviderIdAndEmail(provider, providerId, oldEmail)
+                .orElseThrow(() -> {
+                    log.warn("해당 이메일을 가진 사용자를 찾을 수 없습니다. Provider: {}, ProviderId: {}, OldEmail: {}", provider, providerId, oldEmail);
+                    return new ApiException(ExceptionCode.NON_EXISTENT_EMAIL);
+                });
 
-            log.info("소셜 로그인 정보 업데이트: {}", socialLogin);
-        } else {
-            // SocialLogin 정보가 존재하지 않으면 로깅하여 알립니다.
-            log.warn("해당 이메일을 가진 사용자를 찾을 수 없습니다: {}", oldEmail);
-            throw new ApiException(ExceptionCode.NON_EXISTENT_EMAIL);
-        }
+        // 소셜 로그인 정보 이메일 업데이트
+        socialLogin.updateEmail(newEmail);
+        log.info("소셜 로그인 정보 업데이트: {}", socialLogin);
     }
 }
+
diff --git a/src/main/java/com/ward/ward_server/api/user/service/AuthService.java b/src/main/java/com/ward/ward_server/api/user/service/AuthService.java
index b7d3d3e..a823362 100644
--- a/src/main/java/com/ward/ward_server/api/user/service/AuthService.java
+++ b/src/main/java/com/ward/ward_server/api/user/service/AuthService.java
@@ -234,7 +234,7 @@ private JwtTokens generateJwtTokens(User user) {
             var accessToken = jwtIssuer.issueAccessToken(principal.getUserId(), principal.getEmail(), roles);
             var refreshToken = jwtIssuer.issueRefreshToken();
 
-            refreshTokenService.saveRefreshToken(user, refreshToken);
+            refreshTokenService.saveNewRefreshToken(user, refreshToken);
 
             return new JwtTokens(accessToken, refreshToken);
         } catch (AuthenticationException e) {
diff --git a/src/main/java/com/ward/ward_server/api/user/service/RefreshTokenService.java b/src/main/java/com/ward/ward_server/api/user/service/RefreshTokenService.java
index bbfabdc..33544cd 100644
--- a/src/main/java/com/ward/ward_server/api/user/service/RefreshTokenService.java
+++ b/src/main/java/com/ward/ward_server/api/user/service/RefreshTokenService.java
@@ -14,14 +14,12 @@
 public class RefreshTokenService {
     private final RefreshTokenRepository refreshTokenRepository;
 
-    // 토큰 생성
     @Transactional
-    public void saveRefreshToken(User user, String refreshToken) {
+    public void saveNewRefreshToken(User user, String refreshToken) {
         var refreshTokenEntity = new RefreshToken(refreshToken, user);
         refreshTokenRepository.save(refreshTokenEntity);
     }
 
-    // 토큰 무효화
     @Transactional
     public void invalidateRefreshToken(String refreshToken) {
         var token = refreshTokenRepository.findByToken(refreshToken)
@@ -35,10 +33,9 @@ public RefreshToken findRefreshTokenByToken(String token) {
                 .orElseThrow(() -> new ApiException(ExceptionCode.INVALID_REFRESH_TOKEN));
     }
 
-    // 토큰 갱신
     @Transactional
     public void invalidateAndSaveNewToken(RefreshToken oldToken, String newToken) {
         refreshTokenRepository.delete(oldToken);
-        saveRefreshToken(oldToken.getUser(), newToken);
+        saveNewRefreshToken(oldToken.getUser(), newToken);
     }
 }
diff --git a/src/main/java/com/ward/ward_server/api/user/service/UserService.java b/src/main/java/com/ward/ward_server/api/user/service/UserService.java
index 54fee52..81b5131 100644
--- a/src/main/java/com/ward/ward_server/api/user/service/UserService.java
+++ b/src/main/java/com/ward/ward_server/api/user/service/UserService.java
@@ -12,13 +12,15 @@
 import com.ward.ward_server.api.wishBrand.repository.WishBrandRepository;
 import com.ward.ward_server.api.wishItem.WishItem;
 import com.ward.ward_server.api.wishItem.repository.WishItemRepository;
+import com.ward.ward_server.global.Object.Constants;
+import com.ward.ward_server.global.config.AppleConfig;
+import com.ward.ward_server.global.config.KakaoConfig;
 import com.ward.ward_server.global.exception.ApiException;
 import com.ward.ward_server.global.exception.ExceptionCode;
 import com.ward.ward_server.global.util.AppleClientSecretGenerator;
 import com.ward.ward_server.global.util.ValidationUtils;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.*;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -33,6 +35,12 @@
 @Transactional(readOnly = true)
 public class UserService {
 
+    private static final String AUTHORIZATION_HEADER = "Authorization";
+    private static final String KAKAO_AUTH_PREFIX = "KakaoAK ";
+    private static final String CLIENT_ID_KEY = "client_id=";
+    private static final String CLIENT_SECRET_KEY = "client_secret=";
+    private static final String TOKEN_KEY = "&token=";
+
     private final UserRepository userRepository;
     private final EntryRecordRepository entryRecordRepository;
     private final WishItemRepository wishItemRepository;
@@ -40,27 +48,8 @@ public class UserService {
     private final SocialLoginRepository socialLoginRepository;
     private final RefreshTokenRepository refreshTokenRepository;
     private final RestTemplate restTemplate;
-
-    @Value("${kakao.unlink-url}")
-    private String kakaoUnlinkUrl;
-
-    @Value("${kakao.service-app-admin-key}")
-    private String serviceAppAdminKey;
-
-    @Value("${apple.unlink-url}")
-    private String appleUnlinkUrl;
-
-    @Value("${apple.client-id}")
-    private String appleClientId;
-
-    @Value("${apple.key-id}")
-    private String appleKeyId;
-
-    @Value("${apple.team-id}")
-    private String appleTeamId;
-
-    @Value("${apple.private-key}")
-    private String applePrivateKey;
+    private final KakaoConfig kakaoConfig;
+    private final AppleConfig appleConfig;
 
     public String getNickname(Long userId) {
         return userRepository.findNicknameById(userId)
@@ -90,10 +79,8 @@ public void deleteUser(Long userId) {
         List<RefreshToken> refreshTokens = refreshTokenRepository.findByUserId(userId);
 
         try {
-            // 소셜 로그인 정보 삭제 (카카오)
             disconnectKakao(user);
 
-            // 소셜 로그인 정보 삭제 (애플)
             disconnectApple(user);
 
             // 연관 데이터 일괄 삭제
@@ -111,62 +98,64 @@ public void deleteUser(Long userId) {
     }
 
     private void disconnectKakao(User user) {
-        Optional<SocialLogin> socialLogin = socialLoginRepository.findByUserAndProvider(user, "kakao");
+        Optional<SocialLogin> socialLogin = socialLoginRepository.findByUserAndProvider(user, Constants.KAKAO);
         if (socialLogin.isPresent()) {
             try {
                 long providerId = Long.parseLong(socialLogin.get().getProviderId());
 
                 HttpHeaders headers = new HttpHeaders();
                 headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
-                headers.set("Authorization", "KakaoAK " + serviceAppAdminKey);
+                headers.set(AUTHORIZATION_HEADER, KAKAO_AUTH_PREFIX + kakaoConfig.getServiceAppAdminKey());
 
                 String body = "target_id_type=user_id&target_id=" + providerId;
                 HttpEntity<String> entity = new HttpEntity<>(body, headers);
 
-                ResponseEntity<String> response = restTemplate.exchange(kakaoUnlinkUrl, HttpMethod.POST, entity, String.class);
+                ResponseEntity<String> response = restTemplate.exchange(kakaoConfig.getUnlinkUrl(), HttpMethod.POST, entity, String.class);
 
                 if (response.getStatusCode() != HttpStatus.OK) {
-                    log.error("카카오 계정 연동 해제 실패: {}", response.getStatusCode());
+                    log.error("[UserService] 카카오 계정 연동 해제 실패. HTTP 상태 코드: {}, 사용자 ID: {}", response.getStatusCode(), user.getId());
                     throw new ApiException(ExceptionCode.SOCIAL_DISCONNECT_FAILED, "카카오 계정 연동 해제 실패");
                 }
 
                 socialLoginRepository.delete(socialLogin.get());
             } catch (NumberFormatException e) {
-                log.error("유효하지 않은 카카오 providerId입니다: {}", e.getMessage());
+                log.error("[UserService] 유효하지 않은 카카오 providerId입니다. 사용자 ID: {}, providerId: {}", user.getId(), socialLogin.get().getProviderId());
                 throw new ApiException(ExceptionCode.INVALID_PROVIDER_ID, "유효하지 않은 카카오 providerId입니다.");
             }
         }
     }
 
     private void disconnectApple(User user) {
-        Optional<SocialLogin> socialLogin = socialLoginRepository.findByUserAndProvider(user, "apple");
+        Optional<SocialLogin> socialLogin = socialLoginRepository.findByUserAndProvider(user, Constants.APPLE);
         if (socialLogin.isPresent()) {
             try {
                 String appleRefreshToken = socialLogin.get().getAppleRefreshToken();
                 if (appleRefreshToken == null || appleRefreshToken.isBlank()) {
-                    log.error("애플 리프레시 토큰이 없습니다: {}", user.getId());
+                    log.error("[UserService] 애플 리프레시 토큰이 없습니다. 사용자 ID: {}", user.getId());
                     throw new ApiException(ExceptionCode.MISSING_REFRESH_TOKEN);
                 }
 
-                String clientSecret = AppleClientSecretGenerator.generateClientSecret(appleTeamId, appleClientId, appleKeyId, applePrivateKey);
+                String clientSecret = AppleClientSecretGenerator.generateClientSecret(
+                        appleConfig.getTeamId(), appleConfig.getClientId(), appleConfig.getKeyId(), appleConfig.getPrivateKey()
+                );
 
                 HttpHeaders headers = new HttpHeaders();
                 headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
-                String body = "client_id=" + appleClientId +
-                        "&client_secret=" + clientSecret +
-                        "&token=" + appleRefreshToken;
+                String body = CLIENT_ID_KEY + appleConfig.getClientId() +
+                        CLIENT_SECRET_KEY + clientSecret +
+                        TOKEN_KEY + appleRefreshToken;
                 HttpEntity<String> entity = new HttpEntity<>(body, headers);
 
-                ResponseEntity<String> response = restTemplate.exchange(appleUnlinkUrl, HttpMethod.POST, entity, String.class);
+                ResponseEntity<String> response = restTemplate.exchange(appleConfig.getUnlinkUrl(), HttpMethod.POST, entity, String.class);
 
                 if (response.getStatusCode() != HttpStatus.OK) {
-                    log.error("애플 계정 연동 해제 실패: {}", response.getStatusCode());
+                    log.error("[UserService] 애플 계정 연동 해제 실패. HTTP 상태 코드: {}, 사용자 ID: {}", response.getStatusCode(), user.getId());
                     throw new ApiException(ExceptionCode.SOCIAL_DISCONNECT_FAILED, "애플 계정 연동 해제 실패");
                 }
 
                 socialLoginRepository.delete(socialLogin.get());
             } catch (Exception e) {
-                log.error("애플 계정 연동 해제 중 오류 발생: {}", e.getMessage());
+                log.error("[UserService] 애플 계정 연동 해제 중 오류 발생. 사용자 ID: {}, 오류 메시지: {}", user.getId(), e.getMessage());
                 throw new ApiException(ExceptionCode.SERVER_ERROR, "애플 계정 연동 해제 중 오류 발생");
             }
         }
diff --git a/src/main/java/com/ward/ward_server/api/wishBrand/WishBrandService.java b/src/main/java/com/ward/ward_server/api/wishBrand/WishBrandService.java
index 86c1f32..4832841 100644
--- a/src/main/java/com/ward/ward_server/api/wishBrand/WishBrandService.java
+++ b/src/main/java/com/ward/ward_server/api/wishBrand/WishBrandService.java
@@ -19,6 +19,7 @@
 
 @Service
 @RequiredArgsConstructor
+@Transactional(readOnly = true)
 public class WishBrandService {
     private final WishBrandRepository wishBrandRepository;
     private final BrandRepository brandRepository;
@@ -33,7 +34,6 @@ public void createWishBrand(long userId, long brandId) {
         wishBrandRepository.save(new WishBrand(user, brand));
     }
 
-    @Transactional(readOnly = true)
     public PageResponse<WishBrandResponse> getWishBrandListByUser(long userId, BasicSort basicSort, int page) {
         Page<WishBrandResponse> wishBrandPage = wishBrandRepository.getWishBrandPage(userId, basicSort, PageRequest.of(page, API_PAGE_SIZE));
         return new PageResponse<>(wishBrandPage.getContent(), wishBrandPage);
diff --git a/src/main/java/com/ward/ward_server/api/wishItem/WishItemService.java b/src/main/java/com/ward/ward_server/api/wishItem/WishItemService.java
index 721293a..b76537f 100644
--- a/src/main/java/com/ward/ward_server/api/wishItem/WishItemService.java
+++ b/src/main/java/com/ward/ward_server/api/wishItem/WishItemService.java
@@ -1,9 +1,7 @@
 package com.ward.ward_server.api.wishItem;
 
-import com.ward.ward_server.api.entry.repository.EntryRecordRepository;
 import com.ward.ward_server.api.item.entity.Item;
 import com.ward.ward_server.api.item.repository.ItemRepository;
-import com.ward.ward_server.api.releaseInfo.repository.ReleaseInfoRepository;
 import com.ward.ward_server.api.user.entity.User;
 import com.ward.ward_server.api.user.repository.UserRepository;
 import com.ward.ward_server.api.wishItem.repository.WishItemRepository;
@@ -23,6 +21,7 @@
 @Service
 @Slf4j
 @RequiredArgsConstructor
+@Transactional(readOnly = true)
 public class WishItemService {
     private final WishItemRepository wishItemRepository;
     private final UserRepository userRepository;
@@ -38,7 +37,6 @@ public void createWishItem(long userId, long itemId) {
         wishItemRepository.save(new WishItem(user, item));
     }
 
-    @Transactional(readOnly = true)
     public PageResponse<WishItemResponse> getWishItemListByUser(long userId, BasicSort sort, int page) {
         Page<WishItemResponse> wishItemPage = wishItemRepository.getWishItemPage(userId, sort, PageRequest.of(page, API_PAGE_SIZE));
         return new PageResponse<>(wishItemPage.getContent(), wishItemPage);
diff --git a/src/main/java/com/ward/ward_server/global/config/AppleConfig.java b/src/main/java/com/ward/ward_server/global/config/AppleConfig.java
new file mode 100644
index 0000000..fa305a2
--- /dev/null
+++ b/src/main/java/com/ward/ward_server/global/config/AppleConfig.java
@@ -0,0 +1,18 @@
+package com.ward.ward_server.global.config;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+@Getter
+@Setter
+@Configuration
+@ConfigurationProperties(prefix = "apple")
+public class AppleConfig {
+    private String unlinkUrl;
+    private String clientId;
+    private String keyId;
+    private String teamId;
+    private String privateKey;
+}
diff --git a/src/main/java/com/ward/ward_server/global/config/CrawlerConfig.java b/src/main/java/com/ward/ward_server/global/config/CrawlerConfig.java
new file mode 100644
index 0000000..186a064
--- /dev/null
+++ b/src/main/java/com/ward/ward_server/global/config/CrawlerConfig.java
@@ -0,0 +1,15 @@
+package com.ward.ward_server.global.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+@Component
+public class CrawlerConfig {
+
+    @Value("${crawler.chromeDriverPath}")
+    private String chromeDriverPath;
+
+    public String getChromeDriverPath() {
+        return chromeDriverPath;
+    }
+}
diff --git a/src/main/java/com/ward/ward_server/api/item/webCrawler/CrawlerProperties.java b/src/main/java/com/ward/ward_server/global/config/KakaoConfig.java
similarity index 54%
rename from src/main/java/com/ward/ward_server/api/item/webCrawler/CrawlerProperties.java
rename to src/main/java/com/ward/ward_server/global/config/KakaoConfig.java
index ba3a48f..27ba4c1 100644
--- a/src/main/java/com/ward/ward_server/api/item/webCrawler/CrawlerProperties.java
+++ b/src/main/java/com/ward/ward_server/global/config/KakaoConfig.java
@@ -1,4 +1,4 @@
-package com.ward.ward_server.api.item.webCrawler;
+package com.ward.ward_server.global.config;
 
 import lombok.Getter;
 import lombok.Setter;
@@ -8,7 +8,8 @@
 @Getter
 @Setter
 @Configuration
-@ConfigurationProperties(prefix = "crawler")
-public class CrawlerProperties {
-    private String chromeDriverPath;
+@ConfigurationProperties(prefix = "kakao")
+public class KakaoConfig {
+    private String unlinkUrl;
+    private String serviceAppAdminKey;
 }