diff --git a/apps/backend/src/auth/auth.controller.ts b/apps/backend/src/auth/auth.controller.ts
index aab1384..4cdc878 100644
--- a/apps/backend/src/auth/auth.controller.ts
+++ b/apps/backend/src/auth/auth.controller.ts
@@ -48,16 +48,18 @@ export class AuthController {
 
   // TODO will be deprecated if we use Google OAuth
   @Post('/verify')
-  verifyUser(@Body() body: VerifyUserRequestDTO): void {
-    try {
-      this.authService.verifyUser(body.email, String(body.verificationCode));
-    } catch (e) {
-      throw new BadRequestException(e.message);
-    }
+  async verifyUser(@Body() body: VerifyUserRequestDTO) {
+    return this.authService
+      .verifyUser(body.email, String(body.verificationCode))
+      .catch((err) => {
+        throw new BadRequestException(err.message);
+      });
   }
 
   @Post('/signin')
-  signin(@Body() signInDto: SignInRequestDto): Promise<SignInResponseDto> {
+  async signin(
+    @Body() signInDto: SignInRequestDto,
+  ): Promise<SignInResponseDto> {
     return this.authService.signin(signInDto).catch((err) => {
       throw new UnauthorizedException(err.message);
     });
diff --git a/apps/backend/src/auth/auth.service.ts b/apps/backend/src/auth/auth.service.ts
index 2f3036e..299e052 100644
--- a/apps/backend/src/auth/auth.service.ts
+++ b/apps/backend/src/auth/auth.service.ts
@@ -82,16 +82,22 @@ export class AuthService {
 
   verifyUser(email: string, verificationCode: string): Promise<unknown> {
     return new Promise((resolve, reject) => {
-      return new CognitoUser({
+      const cognitoUser = new CognitoUser({
         Username: email,
         Pool: this.userPool,
-      }).confirmRegistration(verificationCode, true, (err, result) => {
-        if (err) {
-          reject(err);
-        } else {
-          resolve(result);
-        }
       });
+
+      return cognitoUser.confirmRegistration(
+        verificationCode,
+        true,
+        (err, result) => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(result);
+          }
+        },
+      );
     });
   }
 
@@ -108,7 +114,7 @@ export class AuthService {
 
     const cognitoUser = new CognitoUser(userData);
 
-    return new Promise<SignInResponseDto>((resolve, reject) => {
+    return new Promise((resolve, reject) => {
       return cognitoUser.authenticateUser(authenticationDetails, {
         onSuccess: (result) => {
           resolve({
@@ -117,7 +123,6 @@ export class AuthService {
           });
         },
         onFailure: (err) => {
-          console.log(err);
           reject(err);
         },
       });
diff --git a/apps/backend/src/auth/dtos/verify-user.request.dto.ts b/apps/backend/src/auth/dtos/verify-user.request.dto.ts
index dd695d3..5ea5c3f 100644
--- a/apps/backend/src/auth/dtos/verify-user.request.dto.ts
+++ b/apps/backend/src/auth/dtos/verify-user.request.dto.ts
@@ -1,9 +1,9 @@
-import { IsEmail, IsNumber } from 'class-validator';
+import { IsEmail, IsNumberString } from 'class-validator';
 
 export class VerifyUserRequestDTO {
   @IsEmail()
   email: string;
 
-  @IsNumber()
+  @IsNumberString()
   verificationCode: number;
 }