diff --git a/src/internal/domain/definition/error.go b/src/internal/domain/definition/error.go
deleted file mode 100644
index 28f7dbf..0000000
--- a/src/internal/domain/definition/error.go
+++ /dev/null
@@ -1,9 +0,0 @@
-package definition
-
-type ErrorResponse struct {
-	Error string `json:"error"`
-}
-
-func Error(err string) *ErrorResponse {
-	return &ErrorResponse{err}
-}
diff --git a/src/internal/domain/entity/user.go b/src/internal/domain/entity/user.go
deleted file mode 100644
index 2b0b578..0000000
--- a/src/internal/domain/entity/user.go
+++ /dev/null
@@ -1,18 +0,0 @@
-package entity
-
-import "time"
-
-type User struct {
-	ID         int       `json:"id"`
-	Username   string    `json:"username"`
-	Password   string    `json:"password"`
-	CreateDate time.Time `json:"create_date"`
-	ModifyDate time.Time `json:"modify_date"` // FIXME: zero-value issue
-}
-
-var TestUser = &User{
-	ID:         1,
-	Username:   "test",
-	Password:   "test",
-	CreateDate: time.Now(),
-}
diff --git a/src/internal/domain/handler/error.go b/src/internal/domain/handler/error.go
deleted file mode 100644
index abeebd1..0000000
--- a/src/internal/domain/handler/error.go
+++ /dev/null
@@ -1 +0,0 @@
-package handler
diff --git a/src/internal/domain/handler/secret.go b/src/internal/domain/handler/secret.go
deleted file mode 100644
index 1d5c12e..0000000
--- a/src/internal/domain/handler/secret.go
+++ /dev/null
@@ -1,10 +0,0 @@
-package handler
-
-import (
-	"github.com/gofiber/fiber/v2"
-)
-
-func SecretHandler(c *fiber.Ctx) error {
-
-	return nil
-}
diff --git a/src/internal/domain/log.go b/src/internal/domain/log.go
deleted file mode 100644
index 8ce89e4..0000000
--- a/src/internal/domain/log.go
+++ /dev/null
@@ -1,20 +0,0 @@
-package app
-
-import (
-	"log"
-)
-
-const AppName = "identity-service"
-
-func Panic(v ...any) {
-	log.Panicln(AppName+":", v)
-}
-
-func Panicf(format string, v ...any) {
-	log.Panicf(AppName+": "+format, v...)
-}
-
-func Panicln(v ...any) {
-	v = append([]any{AppName + ":"}, v...)
-	log.Panicln(v...)
-}
diff --git a/src/internal/domain/middleware/jwt.go b/src/internal/domain/middleware/jwt.go
deleted file mode 100644
index b161942..0000000
--- a/src/internal/domain/middleware/jwt.go
+++ /dev/null
@@ -1,37 +0,0 @@
-package middleware
-
-import (
-	"os"
-
-	"github.com/gofiber/fiber/v2"
-	jwt "github.com/gofiber/jwt/v2"
-)
-
-// JWTProtected func for specify routes group with JWT authentication.
-// See: https://github.com/gofiber/jwt
-func JWTProtected() func(*fiber.Ctx) error {
-	// Create config for JWT authentication middleware.
-	config := jwt.Config{
-		SigningKey:   []byte(os.Getenv("JWT_SECRET_KEY")),
-		ContextKey:   "jwt", // used in private routes
-		ErrorHandler: jwtError,
-	}
-
-	return jwt.New(config)
-}
-
-func jwtError(c *fiber.Ctx, err error) error {
-	// Return status 400 Bad Request and failed authentication error.
-	if err.Error() == "Missing or malformed JWT" {
-		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
-			"error": true,
-			"msg":   err.Error(),
-		})
-	}
-
-	// Return status 401 Unauthorized and failed authentication error.
-	return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{
-		"error": true,
-		"msg":   err.Error(),
-	})
-}