I don’t have any good resources to share. But what I do is to enable error notifications for all my systems. If there is a unhandled exception, I get an e-mail

I don’t have any good resources to share. But what I do is to enable error notifications for all my systems. If there is a unhandled exception, I get an e-mail and slack notification (this includes forwarding errors from the front-end). That and to log any situation in the code that should not be reached. This works fairly good for errors, for misbehaviour or to spot missing opportunities it is blind though.