Comment by Capricorn2481

> You can do this via stored procs or (better in my experience) by adding an intermediate server process which the applications use, via a publicly documented API, and which then talks to the the database which may provide stored proc access to the intermediate server

I don't see how that is materially different from what the OP said, you're both advocating for a single server in front of the database. We can call it intermediate or not, but the only difference is whether the API is public, so it makes sense to keep business logic in the app code.