Often times that’s not needed if you actually use the full power of PG. CHECK constraints go a long way, and where they don‘t go, PG/PSQL goes pretty much a long way.

For internal or prototypical use cases, that can be totally sufficient, however you‘re right that you‘ll eventually want good error messages, observability and much more other custom logic.

What I‘m still searching for is something that works like Hasura or PostgREST and then offers „upgrades“, first via configuration, later via custom code hooks.

That would be pretty awesome from a migration path perspective.