diff --git a/api/src/main/java/com/backend/backend/controller/UserController.java b/api/src/main/java/com/backend/backend/controller/UserController.java
index becc4d8..172f1e5 100644
--- a/api/src/main/java/com/backend/backend/controller/UserController.java
+++ b/api/src/main/java/com/backend/backend/controller/UserController.java
@@ -19,7 +19,7 @@ public ResponseEntity<CurrentUserDto> getCurrentUser() {
         User currentUser = (User) authentication.getPrincipal();
         CurrentUserDto response = new CurrentUserDto();
         response.setEmail(currentUser.getEmail());
-        response.setFullName(currentUser.getFullName());
+        response.setUserTag(currentUser.getUserTag());
         response.setId(currentUser.getId());
         return ResponseEntity.ok(response);
     }
diff --git a/api/src/main/java/com/backend/backend/dto/CurrentUserDto.java b/api/src/main/java/com/backend/backend/dto/CurrentUserDto.java
index eb3a50c..5f78379 100644
--- a/api/src/main/java/com/backend/backend/dto/CurrentUserDto.java
+++ b/api/src/main/java/com/backend/backend/dto/CurrentUserDto.java
@@ -6,5 +6,5 @@
 public class CurrentUserDto {
     private Long id;
     private String email;
-    private String fullName;
+    private String userTag;
 }
diff --git a/api/src/main/java/com/backend/backend/dto/RegisterUserDto.java b/api/src/main/java/com/backend/backend/dto/RegisterUserDto.java
index af8dce4..d9d23d5 100644
--- a/api/src/main/java/com/backend/backend/dto/RegisterUserDto.java
+++ b/api/src/main/java/com/backend/backend/dto/RegisterUserDto.java
@@ -8,5 +8,5 @@ public class RegisterUserDto {
 
     private String password;
 
-    private String fullName;
+    private String userTag;
 }
diff --git a/api/src/main/java/com/backend/backend/exceptions/GlobalExceptionHandler.java b/api/src/main/java/com/backend/backend/exceptions/GlobalExceptionHandler.java
index cc127c9..9d30180 100644
--- a/api/src/main/java/com/backend/backend/exceptions/GlobalExceptionHandler.java
+++ b/api/src/main/java/com/backend/backend/exceptions/GlobalExceptionHandler.java
@@ -17,7 +17,6 @@ public class GlobalExceptionHandler {
     public ProblemDetail handleSecurityException(Exception exception) {
         ProblemDetail errorDetail = null;
 
-        // TODO send this stack trace to an observability tool
         exception.printStackTrace();
 
         if (exception instanceof BadCredentialsException) {
diff --git a/api/src/main/java/com/backend/backend/model/User.java b/api/src/main/java/com/backend/backend/model/User.java
index b0eaebc..312f310 100644
--- a/api/src/main/java/com/backend/backend/model/User.java
+++ b/api/src/main/java/com/backend/backend/model/User.java
@@ -21,7 +21,7 @@ public class User implements UserDetails {
     private Long id;
     private String email;
     private String password;
-    private String fullName;
+    private String userTag;
 
     @OneToMany(mappedBy = "user")
     private Set<UserBoard> userBoards;
@@ -37,8 +37,8 @@ public String getUsername() {
         return email;
     }
 
-    public User setUsername(String username) {
-        this.email = username;
+    public User setUsername(String email) {
+        this.email = email;
         return this;
     }
 
diff --git a/api/src/main/java/com/backend/backend/service/AuthenticationService.java b/api/src/main/java/com/backend/backend/service/AuthenticationService.java
index d0d2197..eadbc34 100644
--- a/api/src/main/java/com/backend/backend/service/AuthenticationService.java
+++ b/api/src/main/java/com/backend/backend/service/AuthenticationService.java
@@ -29,7 +29,8 @@ public AuthenticationService(
 
     public User signup(RegisterUserDto input) {
         User user = new User()
-                .setFullName(input.getFullName())
+                .setUserTag(input.getUserTag())
+                .setUsername(input.getEmail())
                 .setEmail(input.getEmail())
                 .setPassword(passwordEncoder.encode(input.getPassword()));