diff --git a/backend/handlers/chat_api.go b/backend/handlers/chat_api.go
index 2e3540cb..918d0f3e 100644
--- a/backend/handlers/chat_api.go
+++ b/backend/handlers/chat_api.go
@@ -47,7 +47,7 @@ func HandleChatRoomHandler(c *websocket.Conn, markerID, reqID string) {
 
 	defer func() {
 		// On disconnect, remove the client from the room
-		services.WsRoomManager.RemoveWsFromRoom(markerID, clientId, c)
+		services.WsRoomManager.RemoveWsFromRoom(markerID, clientId)
 		// services.RemoveConnectionFromRedis(markerID, reqID)
 
 		// Broadcast leave message
diff --git a/backend/handlers/marker_api.go b/backend/handlers/marker_api.go
index 1701fc8f..12ef5339 100644
--- a/backend/handlers/marker_api.go
+++ b/backend/handlers/marker_api.go
@@ -22,7 +22,7 @@ import (
 )
 
 var (
-	// cache to store encoded marker data
+	// MarkersLocalCache cache to store encoded marker data
 	MarkersLocalCache []byte // 400 kb is fine here
 	CacheMutex        sync.RWMutex
 )
@@ -76,11 +76,6 @@ func RegisterMarkerRoutes(api fiber.Router) {
 }
 
 func createMarkerWithPhotosHandler(c *fiber.Ctx) error {
-	// go services.ResetCache(services.ALL_MARKERS_KEY)
-	CacheMutex.Lock()
-	MarkersLocalCache = nil
-	CacheMutex.Unlock()
-
 	// Parse the multipart form
 	form, err := c.MultipartForm()
 	if err != nil {
@@ -94,21 +89,52 @@ func createMarkerWithPhotosHandler(c *fiber.Ctx) error {
 	}
 
 	// Location Must Be Inside South Korea
-	if !util.IsInSouthKoreaPrecisely(latitude, longitude) {
-		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "Operations are only allowed within South Korea."})
-	}
+	// if !util.IsInSouthKoreaPrecisely(latitude, longitude) {
+	// 	return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "Operations are only allowed within South Korea."})
+	// }
+
+	errorChan := make(chan error)
+	defer close(errorChan)
+
+	go func() {
+		if inSKorea := util.IsInSouthKoreaPrecisely(latitude, longitude); !inSKorea {
+			errorChan <- fmt.Errorf("operation is only allowed within South Korea")
+		} else {
+			errorChan <- nil
+		}
+	}()
 
 	// Checking if there's a marker close to the latitude and longitude
-	if nearby, _ := services.IsMarkerNearby(latitude, longitude, 10); nearby {
-		return c.Status(fiber.StatusConflict).JSON(fiber.Map{"error": "There is a marker already nearby."})
-	}
+	go func() {
+		if nearby, _ := services.IsMarkerNearby(latitude, longitude, 10); nearby {
+			errorChan <- fmt.Errorf("there is a marker already nearby")
+		} else {
+			errorChan <- nil
+		}
+	}()
 
-	// Set default description if it's empty or not provided
 	description := GetDescriptionFromForm(form)
-	if containsBadWord, _ := util.CheckForBadWords(description); containsBadWord {
-		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Comment contains inappropriate content."})
+
+	// Concurrent check for bad words
+	go func() {
+		if containsBadWord, _ := util.CheckForBadWords(description); containsBadWord {
+			errorChan <- fmt.Errorf("comment contains inappropriate content")
+		} else {
+			errorChan <- nil
+		}
+	}()
+
+	for i := 0; i < 3; i++ {
+		if err := <-errorChan; err != nil {
+			return c.Status(mapErrorToStatus(err.Error())).JSON(fiber.Map{"error": err.Error()})
+		}
 	}
 
+	// no errors
+	CacheMutex.Lock()
+	MarkersLocalCache = nil
+	CacheMutex.Unlock()
+
 	userId := c.Locals("userID").(int)
 
 	marker, err := services.CreateMarkerWithPhotos(&dto.MarkerRequest{
@@ -605,3 +631,14 @@ func GetMarkerIDFromForm(form *multipart.Form) string {
 	}
 	return ""
 }
+
+func mapErrorToStatus(errorMessage string) int {
+	switch errorMessage {
+	case "There is a marker already nearby.":
+		return fiber.StatusConflict
+	case "Comment contains inappropriate content.":
+		return fiber.StatusBadRequest
+	default:
+		return fiber.StatusInternalServerError
+	}
+}
diff --git a/backend/main.go b/backend/main.go
index 3d13fa69..5516121a 100644
--- a/backend/main.go
+++ b/backend/main.go
@@ -243,6 +243,7 @@ func setUpMiddlewares(app *fiber.App) {
 		Level: compress.LevelBestSpeed,
 	}))
 
+	// ContentSecurityPolicy: "default-src 'self'; script-src 'self' 'unsafe-inline'; object-src 'none'"
 	app.Use(helmet.New(helmet.Config{XSSProtection: "1; mode=block"}))
 	app.Use(limiter.New(limiter.Config{
 		Next: func(c *fiber.Ctx) bool {
@@ -368,8 +369,8 @@ func setUpGlobals() {
 
 	// Initialize global variables
 	setTokenExpirationTime()
-	services.AWS_REGION = os.Getenv("AWS_REGION")
-	services.S3_BUCKET_NAME = os.Getenv("AWS_BUCKET_NAME")
+	services.AwsRegion = os.Getenv("AWS_REGION")
+	services.S3BucketName = os.Getenv("AWS_BUCKET_NAME")
 	util.LOGIN_TOKEN_COOKIE = os.Getenv("TOKEN_COOKIE")
 }
 
@@ -384,7 +385,7 @@ func setTokenExpirationTime() {
 	}
 
 	// Assign the converted duration to the global variable
-	services.TOKEN_DURATION = time.Duration(durationInt) * time.Hour
+	services.TokenDuration = time.Duration(durationInt) * time.Hour
 }
 
 // countAPIs counts the number of APIs in a Fiber app
diff --git a/backend/revive.toml b/backend/revive.toml
new file mode 100644
index 00000000..f2ca84d9
--- /dev/null
+++ b/backend/revive.toml
@@ -0,0 +1,29 @@
+ignoreGeneratedHeader = false
+severity = "warning"
+confidence = 0.8
+errorCode = 0
+warningCode = 0
+
+[rule.blank-imports]
+[rule.context-as-argument]
+[rule.context-keys-type]
+[rule.dot-imports]
+[rule.error-return]
+[rule.error-strings]
+[rule.error-naming]
+[rule.exported]
+[rule.increment-decrement]
+[rule.var-naming]
+[rule.var-declaration]
+[rule.package-comments]
+[rule.range]
+[rule.receiver-naming]
+[rule.time-naming]
+[rule.unexported-return]
+[rule.indent-error-flow]
+[rule.errorf]
+[rule.empty-block]
+[rule.superfluous-else]
+[rule.unused-parameter]
+[rule.unreachable-code]
+[rule.redefines-builtin-id]
\ No newline at end of file
diff --git a/backend/services/chat_conn_service.go b/backend/services/chat_conn_service.go
index ef55b6e8..e4e445ee 100644
--- a/backend/services/chat_conn_service.go
+++ b/backend/services/chat_conn_service.go
@@ -24,8 +24,8 @@ func (manager *RoomConnectionManager) SaveConnection(markerID, clientId string,
 	newConn := &ChulbongConn{
 		Socket:       conn,
 		UserID:       clientId,
-		Send:         make(chan []byte, 256), // Buffered channel
-		InActiveChan: make(chan struct{}, 10),
+		Send:         make(chan []byte, 10), // Buffered channel
+		InActiveChan: make(chan struct{}),
 	}
 	newConn.UpdateLastSeen()
 
@@ -233,7 +233,7 @@ func RemoveConnectionFromRedis(markerID, xRequestID string) {
 }
 
 // RemoveConnection removes a WebSocket connection associated with a id
-func (manager *RoomConnectionManager) RemoveWsFromRoom(markerID, clientId string, conn *websocket.Conn) {
+func (manager *RoomConnectionManager) RemoveWsFromRoom(markerID, clientId string) {
 	// manager.mu.Lock()         // Lock at the start of the method
 	// defer manager.mu.Unlock() // Unlock when the method returns
 
diff --git a/backend/services/chat_process_service.go b/backend/services/chat_process_service.go
index cef2c310..200b5f03 100644
--- a/backend/services/chat_process_service.go
+++ b/backend/services/chat_process_service.go
@@ -10,6 +10,7 @@ import (
 	"github.com/goccy/go-json"
 )
 
+// ProcessMessageFromSubscription processes a message from a Redis subscription
 func ProcessMessageFromSubscription(msg []byte) {
 	var broadcastMsg dto.BroadcastMessage
 	err := json.Unmarshal(msg, &broadcastMsg)
diff --git a/backend/services/chat_service.go b/backend/services/chat_service.go
index 3ed8f2cc..331e8435 100644
--- a/backend/services/chat_service.go
+++ b/backend/services/chat_service.go
@@ -33,7 +33,7 @@ var (
 	retryCtx, _ = context.WithCancel(context.Background())
 )
 
-var WsRoomManager *RoomConnectionManager = NewRoomConnectionManager()
+var WsRoomManager = NewRoomConnectionManager()
 
 type ChulbongConn struct {
 	Socket       *websocket.Conn
@@ -185,7 +185,7 @@ func (manager *RoomConnectionManager) BroadcastMessage(message []byte, userId, r
 		return
 	}
 
-	manager.connections.Range(func(key string, conns []*ChulbongConn) bool {
+	manager.connections.Range(func(_ string, conns []*ChulbongConn) bool {
 		// Iterate over the connections and send the message
 		for _, conn := range conns {
 			select {
diff --git a/backend/services/marker_facilities_service.go b/backend/services/marker_facilities_service.go
index a59d871d..e2c3150b 100644
--- a/backend/services/marker_facilities_service.go
+++ b/backend/services/marker_facilities_service.go
@@ -24,14 +24,14 @@ const (
 )
 
 var (
-	KAKAO_AK = os.Getenv("KAKAO_AK")
+	KakaoAK = os.Getenv("KAKAO_AK")
 
 	HTTPClient = &http.Client{
 		Timeout: 10 * time.Second, // Set a timeout to avoid hanging requests indefinitely
 	}
 
-	IS_WATER_URL = os.Getenv("IS_WATER_API")
-	IS_WATER_KEY = os.Getenv("IS_WATER_API_KEY")
+	IsWaterURL = os.Getenv("IS_WATER_API")
+	IsWaterKEY = os.Getenv("IS_WATER_API_KEY")
 )
 
 // GetFacilitiesByMarkerID retrieves facilities for a given marker ID.
@@ -111,7 +111,7 @@ func FetchAddressFromAPI(latitude, longitude float64) (string, error) {
 		return "-1", fmt.Errorf("creating request: %w", err)
 	}
 
-	req.Header.Add("Authorization", "KakaoAK "+KAKAO_AK)
+	req.Header.Add("Authorization", "KakaoAK "+KakaoAK)
 	resp, err := HTTPClient.Do(req)
 	if err != nil {
 		return "-1", fmt.Errorf("executing request: %w", err)
@@ -151,7 +151,7 @@ func FetchXYFromAPI(address string) (float64, float64, error) {
 		return 0.0, 0.0, fmt.Errorf("creating request: %w", err)
 	}
 
-	req.Header.Add("Authorization", "KakaoAK "+KAKAO_AK)
+	req.Header.Add("Authorization", "KakaoAK "+KakaoAK)
 	resp, err := HTTPClient.Do(req)
 	if err != nil {
 		return 0.0, 0.0, fmt.Errorf("executing request: %w", err)
@@ -199,7 +199,7 @@ func FetchRegionFromAPI(latitude, longitude float64) (string, error) {
 		return "-1", fmt.Errorf("creating request: %w", err)
 	}
 
-	req.Header.Add("Authorization", "KakaoAK "+KAKAO_AK)
+	req.Header.Add("Authorization", "KakaoAK "+KakaoAK)
 	resp, err := HTTPClient.Do(req)
 	if err != nil {
 		return "-1", fmt.Errorf("executing request: %w", err)
@@ -275,7 +275,7 @@ func FetchWeatherFromAddress(latitude, longitude float64) (*kakao.WeatherRequest
 
 // FetchRegionWaterInfo checks if latitude/longitude is in the water possibly.
 func FetchRegionWaterInfo(latitude, longitude float64) (bool, error) {
-	reqURL := fmt.Sprintf("%s?latitude=%f&longitude=%f&rapidapi-key=%s", IS_WATER_URL, latitude, longitude, IS_WATER_KEY)
+	reqURL := fmt.Sprintf("%s?latitude=%f&longitude=%f&rapidapi-key=%s", IsWaterURL, latitude, longitude, IsWaterKEY)
 	req, err := http.NewRequest(http.MethodGet, reqURL, nil)
 	if err != nil {
 		return false, fmt.Errorf("creating request: %w", err)
diff --git a/backend/services/marker_location_service.go b/backend/services/marker_location_service.go
index 885fa363..34804553 100644
--- a/backend/services/marker_location_service.go
+++ b/backend/services/marker_location_service.go
@@ -85,7 +85,7 @@ func FindRankedMarkersInCurrentArea(lat, long float64, distance, limit int) ([]d
 	}
 
 	ctx := context.Background()
-	floatMin := float64(MIN_CLICK_RANK)
+	floatMin := float64(MinClickRank)
 
 	result, _ := RedisStore.Do(ctx, RedisStore.B().Zmscore().Key("marker_clicks").Member(markerIDs...).Build()).AsFloatSlice()
 	rankedMarkers := make([]dto.MarkerWithDistance, 0, len(result))
diff --git a/backend/services/marker_rank_service.go b/backend/services/marker_rank_service.go
index 0f59aac8..b8261d9d 100644
--- a/backend/services/marker_rank_service.go
+++ b/backend/services/marker_rank_service.go
@@ -20,40 +20,44 @@ import (
 )
 
 // 클릭 이벤트를 저장할 임시 저장소
-var clickEventBuffer = csmap.Create(
-	csmap.WithShardCount[int, int](64),
-	csmap.WithCustomHasher[int, int](func(key int) uint64 {
-		// Convert int to a byte slice
-		bs := make([]byte, 8)
-		binary.LittleEndian.PutUint64(bs, uint64(key))
-		return xxh3.Hash(bs)
-	}),
+var (
+	ClickEventBuffer = csmap.Create(
+		csmap.WithShardCount[int, int](64),
+		csmap.WithCustomHasher[int, int](func(key int) uint64 {
+			// Convert int to a byte slice
+			bs := make([]byte, 8)
+			binary.LittleEndian.PutUint64(bs, uint64(key))
+			return xxh3.Hash(bs)
+		}),
+	)
+
+	SketchedLocations = csmap.Create(
+		csmap.WithShardCount[string, *hyperloglog.Sketch](64),
+		csmap.WithCustomHasher[string, *hyperloglog.Sketch](func(key string) uint64 {
+			return xxh3.HashString(key)
+		}),
+	)
 )
 
-var SketchedLocations = csmap.Create(
-	csmap.WithShardCount[string, *hyperloglog.Sketch](64),
-	csmap.WithCustomHasher[string, *hyperloglog.Sketch](func(key string) uint64 {
-		return xxh3.HashString(key)
-	}),
+const (
+	RankUpdateTime = 3 * time.Minute
+	MinClickRank   = 5
 )
 
-const RANK_UPDATE_TIME = 3 * time.Minute
-const MIN_CLICK_RANK = 5
-
 // 클릭 이벤트를 버퍼에 추가하는 함수
 func BufferClickEvent(markerID int) {
 	// 현재 클릭 수 조회
 	// 마커 ID가 존재하지 않으면 클릭 수를 1로 설정
-	clickEventBuffer.SetIfAbsent(markerID, 1)
+	ClickEventBuffer.SetIfAbsent(markerID, 1)
 
-	actual, ok := clickEventBuffer.Load(markerID)
+	actual, ok := ClickEventBuffer.Load(markerID)
 	if !ok {
 		return
 	}
 
 	// 마커 ID가 존재하면 클릭 수를 1 증가
 	newClicks := actual + 1
-	clickEventBuffer.Store(markerID, newClicks)
+	ClickEventBuffer.Store(markerID, newClicks)
 }
 
 func SaveUniqueVisitor(markerID string, uniqueUser string) {
@@ -99,13 +103,13 @@ func GetAllUniqueVisitorCounts() map[string]int {
 // 정해진 시간 간격마다 클릭 이벤트 배치 처리를 실행하는 함수
 func ProcessClickEventsBatch() {
 	// 일정 시간 간격으로 배치 처리 실행
-	ticker := time.NewTicker(RANK_UPDATE_TIME)
+	ticker := time.NewTicker(RankUpdateTime)
 	defer ticker.Stop() // 함수가 반환될 때 ticker를 정지
 
 	for range ticker.C {
-		IncrementMarkerClicks(clickEventBuffer)
+		IncrementMarkerClicks(ClickEventBuffer)
 		// 처리 후 버퍼 초기화
-		clickEventBuffer.Clear()
+		ClickEventBuffer.Clear()
 	}
 }
 
@@ -136,7 +140,7 @@ func GetTopMarkers(limit int) []dto.MarkerSimpleWithAddr {
 	ctx := context.Background()
 
 	// Convert minClickRank to string and prepare for the ZRangeByScore command
-	minScore := strconv.Itoa(MIN_CLICK_RANK + 1) // "+1" to adjust for exclusive minimum
+	minScore := strconv.Itoa(MinClickRank + 1) // "+1" to adjust for exclusive minimum
 
 	// Use ZREVRANGEBYSCORE to get marker IDs in descending order based on score
 	markerScores, err := RedisStore.Do(ctx, RedisStore.B().Zrevrangebyscore().
diff --git a/backend/services/notification_service.go b/backend/services/notification_service.go
index 5047fddf..6b0718d6 100644
--- a/backend/services/notification_service.go
+++ b/backend/services/notification_service.go
@@ -62,7 +62,7 @@ func PostNotification(userId, notificationType, title, message string, metadata
 }
 
 // GetNotifications retrieves notifications for a specific user (unviewed)
-func GetNotifications(userId string) ([]NotificationRedis, error) {
+func GetNotifications(userID string) ([]NotificationRedis, error) {
 	var notifications []Notification
 	const query = `(SELECT * FROM Notifications 
 		WHERE UserId = ? AND Viewed = FALSE 
@@ -71,7 +71,7 @@ func GetNotifications(userId string) ([]NotificationRedis, error) {
 		(SELECT * FROM Notifications 
 		WHERE NotificationType IN ('NewMarker', 'System', 'Other') AND Viewed = FALSE 
 		ORDER BY CreatedAt DESC)`
-	err := database.DB.Select(&notifications, query, userId)
+	err := database.DB.Select(&notifications, query, userID)
 	if err != nil {
 		return nil, err
 	}
@@ -89,7 +89,7 @@ func GetNotifications(userId string) ([]NotificationRedis, error) {
 					results[idx] = mapToNotificationRedis(notif)
 				}
 			} else {
-				viewed, err := IsNotificationViewed(notif.NotificationId, userId)
+				viewed, err := IsNotificationViewed(notif.NotificationId, userID)
 				if err != nil {
 					errors <- err
 					return
diff --git a/backend/services/redis_services.go b/backend/services/redis_services.go
index 563ea821..4530ec37 100644
--- a/backend/services/redis_services.go
+++ b/backend/services/redis_services.go
@@ -98,7 +98,7 @@ func ResetCache(key string) error {
 func ResetAllCache(pattern string) error {
 	ctx := context.Background()
 
-	var cursor uint64 = 0
+	var cursor uint64
 	for {
 		// Build the SCAN command with the current cursor
 		scanCmd := RedisStore.B().Scan().Cursor(cursor).Match(pattern).Count(10).Build()
diff --git a/backend/services/s3_service.go b/backend/services/s3_service.go
index afabb987..019fcad9 100644
--- a/backend/services/s3_service.go
+++ b/backend/services/s3_service.go
@@ -14,8 +14,10 @@ import (
 	"github.com/google/uuid"
 )
 
-var AWS_REGION string
-var S3_BUCKET_NAME string
+var (
+	AwsRegion    string
+	S3BucketName string
+)
 
 func UploadFileToS3(folder string, file *multipart.FileHeader) (string, error) {
 	// Open the uploaded file
@@ -27,7 +29,7 @@ func UploadFileToS3(folder string, file *multipart.FileHeader) (string, error) {
 
 	// Load the AWS credentials
 	cfg, err := config.LoadDefaultConfig(context.TODO(),
-		config.WithRegion(AWS_REGION),
+		config.WithRegion(AwsRegion),
 	)
 	if err != nil {
 		return "", fmt.Errorf("could not load AWS credentials: %w", err)
@@ -48,7 +50,7 @@ func UploadFileToS3(folder string, file *multipart.FileHeader) (string, error) {
 
 	// Upload the file to S3
 	_, err = s3Client.PutObject(context.TODO(), &s3.PutObjectInput{
-		Bucket: &S3_BUCKET_NAME,
+		Bucket: &S3BucketName,
 		Key:    &key,
 		Body:   fileData,
 	})
@@ -57,7 +59,7 @@ func UploadFileToS3(folder string, file *multipart.FileHeader) (string, error) {
 	}
 
 	// Construct the file URL
-	fileURL := fmt.Sprintf("https://%s.s3.amazonaws.com/%s", S3_BUCKET_NAME, key)
+	fileURL := fmt.Sprintf("https://%s.s3.amazonaws.com/%s", S3BucketName, key)
 
 	return fileURL, nil
 }
@@ -78,7 +80,7 @@ func DeleteDataFromS3(dataURL string) error {
 		key = strings.TrimPrefix(parsedURL.Path, "/")
 	} else {
 		// It's not a valid URL, treat it as a key
-		bucketName = S3_BUCKET_NAME
+		bucketName = S3BucketName
 		key = dataURL
 	}
 
@@ -88,7 +90,7 @@ func DeleteDataFromS3(dataURL string) error {
 
 	// Load the AWS credentials
 	cfg, err := config.LoadDefaultConfig(context.TODO(),
-		config.WithRegion(AWS_REGION),
+		config.WithRegion(AwsRegion),
 	)
 	if err != nil {
 		return fmt.Errorf("could not load AWS credentials: %w", err)
@@ -144,7 +146,7 @@ func FetchAllPhotoURLsFromDB() ([]string, error) {
 func ListAllObjectsInS3() ([]string, error) {
 	// Load the AWS credentials
 	cfg, err := config.LoadDefaultConfig(context.TODO(),
-		config.WithRegion(AWS_REGION),
+		config.WithRegion(AwsRegion),
 	)
 	if err != nil {
 		return nil, fmt.Errorf("error loading AWS config: %w", err)
@@ -152,7 +154,7 @@ func ListAllObjectsInS3() ([]string, error) {
 
 	s3Client := s3.NewFromConfig(cfg)
 	input := &s3.ListObjectsV2Input{
-		Bucket: &S3_BUCKET_NAME,
+		Bucket: &S3BucketName,
 	}
 
 	var s3Keys []string
diff --git a/backend/services/scheduler_service.go b/backend/services/scheduler_service.go
index d0dec96b..d50d1038 100644
--- a/backend/services/scheduler_service.go
+++ b/backend/services/scheduler_service.go
@@ -19,7 +19,7 @@ func RunAllCrons() {
 	CronResetClickRanking()
 	CronOrphanedPhotosCleanup()
 	CronCleanUpOldDirs()
-	CronProcessClickEventsBatch(RANK_UPDATE_TIME)
+	CronProcessClickEventsBatch(RankUpdateTime)
 }
 
 // CronService holds a reference to a cron scheduler and its related setup.
@@ -115,7 +115,7 @@ func CronProcessClickEventsBatch(interval time.Duration) {
 	// spec = "*/1 * * * *"
 
 	_, err := c.Schedule(spec, func() {
-		IncrementMarkerClicks(clickEventBuffer)
+		IncrementMarkerClicks(ClickEventBuffer)
 		// 처리 후 버퍼 초기화
 		// clickEventBuffer.Clear()
 	})
diff --git a/backend/services/smtp_service.go b/backend/services/smtp_service.go
index 70ec06f4..abfe3803 100644
--- a/backend/services/smtp_service.go
+++ b/backend/services/smtp_service.go
@@ -191,8 +191,8 @@ func SendPasswordResetEmail(to, token string) error {
 	headers := fmt.Sprintf("From: %s\r\nTo: %s\r\nSubject: Password Reset for chulbong-kr\r\nMIME-Version: 1.0;\r\nContent-Type: text/html; charset=\"UTF-8\";\r\n\r\n", smtpUsername, to)
 
 	// Replace the {{RESET_LINK}} placeholder with the actual reset link
-	clientUrl := fmt.Sprintf("%s?token=%s&email=%s", frontendResetRouter, token, to)
-	htmlBody := strings.Replace(emailTemplateForReset, "{{RESET_LINK}}", clientUrl, -1)
+	clientURL := fmt.Sprintf("%s?token=%s&email=%s", frontendResetRouter, token, to)
+	htmlBody := strings.Replace(emailTemplateForReset, "{{RESET_LINK}}", clientURL, -1)
 
 	// Combine headers and HTML body into a single raw email message
 	message := []byte(headers + htmlBody)
diff --git a/backend/services/token_service.go b/backend/services/token_service.go
index 76dd3fdc..e0207a3f 100644
--- a/backend/services/token_service.go
+++ b/backend/services/token_service.go
@@ -14,7 +14,7 @@ func GenerateAndSaveToken(userID int) (string, error) {
 		return "", err
 	}
 
-	expiresAt := time.Now().Add(TOKEN_DURATION) // Use the global duration.
+	expiresAt := time.Now().Add(TokenDuration) // Use the global duration.
 	err = SaveOrUpdateOpaqueToken(userID, token, expiresAt)
 	if err != nil {
 		return "", err
diff --git a/backend/services/user_service.go b/backend/services/user_service.go
index 782ccd87..76aabdaa 100644
--- a/backend/services/user_service.go
+++ b/backend/services/user_service.go
@@ -22,8 +22,8 @@ import (
 )
 
 var (
-	TOKEN_DURATION         time.Duration
-	NAVER_EMAIL_VERIFY_URL = os.Getenv("NAVER_EMAIL_VERIFY_URL")
+	TokenDuration       time.Duration
+	NaverEmailVerifyURL = os.Getenv("NAVER_EMAIL_VERIFY_URL")
 
 	userRepo = repository.NewUserRepository()
 )
@@ -364,7 +364,7 @@ func GetUserFromContext(c *fiber.Ctx) (*dto.UserData, error) {
 // VerifyNaverEmail can check naver email existence before sending
 func VerifyNaverEmail(naverAddress string) (bool, error) {
 	naverAddress = strings.Split(naverAddress, "@naver.com")[0]
-	reqURL := fmt.Sprintf("%s=%s", NAVER_EMAIL_VERIFY_URL, naverAddress)
+	reqURL := fmt.Sprintf("%s=%s", NaverEmailVerifyURL, naverAddress)
 	req, err := http.NewRequest(http.MethodGet, reqURL, nil)
 	if err != nil {
 		return false, fmt.Errorf("creating request: %w", err)
@@ -393,9 +393,9 @@ func VerifyNaverEmail(naverAddress string) (bool, error) {
 	// Check if the body is non-empty and ends with 'N'
 	if len(bodyString) > 0 && bodyString[len(bodyString)-1] == 'N' {
 		return true, nil
-	} else {
-		return false, nil
 	}
+
+	return false, nil
 }
 
 // private