diff --git a/knockoutwhistfrontend b/knockoutwhistfrontend
index c2dfa0e..cd950e9 160000
--- a/knockoutwhistfrontend
+++ b/knockoutwhistfrontend
@@ -1 +1 @@
-Subproject commit c2dfa0e701db7c7471392a6ddd4e90503ecb2de2
+Subproject commit cd950e952117cebe0ec46a18fc5b2cf90b247766
diff --git a/knockoutwhistweb/app/controllers/OpenIDController.scala b/knockoutwhistweb/app/controllers/OpenIDController.scala
index 589d0d9..463fb82 100644
--- a/knockoutwhistweb/app/controllers/OpenIDController.scala
+++ b/knockoutwhistweb/app/controllers/OpenIDController.scala
@@ -58,17 +58,33 @@ class OpenIDController @Inject()(
         } yield {
           openIDService.exchangeCodeForTokens(provider, authCode, sessionState.get).flatMap {
             case Some(tokenResponse) =>
-              openIDService.getUserInfo(provider, tokenResponse.accessToken).map {
+              openIDService.getUserInfo(provider, tokenResponse.accessToken).flatMap {
                 case Some(userInfo) =>
-                  // Store user info in session for username selection
-                  Redirect(config.get[String]("openid.selectUserRoute"))
-                    .withSession(
-                      "oauth_user_info" -> Json.toJson(userInfo).toString(),
-                      "oauth_provider" -> provider,
-                      "oauth_access_token" -> tokenResponse.accessToken
-                    )
+                  // Check if user already exists
+                  userManager.authenticateOpenID(provider, userInfo.id) match {
+                    case Some(user) =>
+                      // User already exists, log them in
+                      val sessionToken = sessionManager.createSession(user)
+                      Future.successful(Redirect(config.getOptional[String]("openid.mainRoute").getOrElse("/"))
+                        .withCookies(Cookie(
+                          name = "accessToken",
+                          value = sessionToken,
+                          httpOnly = true,
+                          secure = false,
+                          sameSite = Some(Lax)
+                        ))
+                        .removingFromSession("oauth_state", "oauth_nonce", "oauth_provider", "oauth_access_token"))
+                    case None =>
+                      // New user, redirect to username selection
+                      Future.successful(Redirect(config.get[String]("openid.selectUserRoute"))
+                        .withSession(
+                          "oauth_user_info" -> Json.toJson(userInfo).toString(),
+                          "oauth_provider" -> provider,
+                          "oauth_access_token" -> tokenResponse.accessToken
+                        ))
+                  }
                 case None =>
-                  Redirect("/login").flashing("error" -> "Failed to retrieve user information")
+                  Future.successful(Redirect("/login").flashing("error" -> "Failed to retrieve user information"))
               }
             case None =>
               Future.successful(Redirect("/login").flashing("error" -> "Failed to exchange authorization code"))
diff --git a/knockoutwhistweb/conf/META-INF/persistence.xml b/knockoutwhistweb/conf/META-INF/persistence.xml
index 6cea33f..19cd2cf 100644
--- a/knockoutwhistweb/conf/META-INF/persistence.xml
+++ b/knockoutwhistweb/conf/META-INF/persistence.xml
@@ -12,7 +12,6 @@
 
         <properties>
             <!-- Hibernate specific settings -->
-            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
             <property name="hibernate.hbm2ddl.auto" value="update"/>
             <property name="hibernate.archive.autodetection" value="class"/>
             <property name="hibernate.show_sql" value="false"/>
diff --git a/knockoutwhistweb/conf/application.conf b/knockoutwhistweb/conf/application.conf
index 6f59db2..6ab3ea6 100644
--- a/knockoutwhistweb/conf/application.conf
+++ b/knockoutwhistweb/conf/application.conf
@@ -29,6 +29,7 @@ play.filters.cors {
 # Local Development OpenID Connect Configuration
 openid {
   selectUserRoute="http://localhost:5173/select-username"
+  mainRoute="http://localhost:5173/"
 
   discord {
     clientId = ${?DISCORD_CLIENT_ID}
diff --git a/knockoutwhistweb/conf/prod.conf b/knockoutwhistweb/conf/prod.conf
index 43afc89..9a2a50f 100644
--- a/knockoutwhistweb/conf/prod.conf
+++ b/knockoutwhistweb/conf/prod.conf
@@ -18,6 +18,7 @@ play.filters.cors {
 openid {
 
   selectUserRoute="https://knockout.janis-eccarius.de/select-username"
+  mainRoute="https://knockout.janis-eccarius.de/"
 
   discord {
     clientId = ${?DISCORD_CLIENT_ID}
diff --git a/knockoutwhistweb/conf/staging.conf b/knockoutwhistweb/conf/staging.conf
index ca35c7b..b241619 100644
--- a/knockoutwhistweb/conf/staging.conf
+++ b/knockoutwhistweb/conf/staging.conf
@@ -15,6 +15,7 @@ play.filters.cors {
 openid {
 
   selectUserRoute="https://st.knockout.janis-eccarius.de/select-username"
+  mainRoute="https://st.knockout.janis-eccarius.de/"
 
   discord {
     clientId = ${?DISCORD_CLIENT_ID}