Nice, thank you for the insight.

I can tell that the on-premises will be deployed on AWS accounts. We can manage the resources ourselves.

We have few fanouts that can be refactored. So Redis/Valkey for SQS is OK, hopefully it can also cover our SNS use case.

I am afraid Kubernetes is overkill for our lambda needs.

If we manage to bundle our whole app in one server and have only 1-2 clients on -premise, do you still suggest Kubernetes or a simpler rsync on all servers is enough?

Also, should we have a separate database instance for each client, or a Postgres cluster sharded? The latter seams more manageable.