Cognito is getting better every day, but there are still a few limitations which need to be addressed.
- Logout (revoking tokens immediately and broadcasting this to external services (API Gateway, for instance))
- RefreshToken Rotation -> https://forums.aws.amazon.com/thread.jspa?messageID=948267󧠫
But Cognito is already a robust solution for many use cases, with a good pricing model.
Thanks