In a typical CRUD web app, any query that takes milliseconds instead of microseconds should be viewed with suspicion.

In a more charitable interpretation, maybe the parent is talking about sub-100ms total round trip time for an API call over the public internet.

But OP never said it's a CRUD app. Maybe OP did some experimentation with OLAP use cases.

OP here. Roughly 50GB in db size. Fairly standard queries (full-text search + filters). Most queries are on the order of 10-100ms. Some more complex ones involving business logic exceeds 100ms.

This is well within my budget, but it sounds like there might be room for improvements?

Regardless of your use case, EXPLAIN ANALYZE can show you whether there's any room for improvement.