I think using Firebase Realtime Database to send real-time updates might be applicable in your setup and it works well with App Engine(Standard). I suggest you go through this doc[1].
[1]https://cloud.google.com/solutions/using-firebase-real-time-events-app-engine -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/602eb9d0-d46f-45cd-91dd-a59eddd0ef88%40googlegroups.com.
