I don't think people often switch from Postgres to SQLite, it's probably more common (and much easier) to prototype with SQLite lite first and then switch. If

I don't think people often switch from Postgres to SQLite, it's probably more common (and much easier) to prototype with SQLite lite first and then switch. If by referential integrity you just mean FK constraints, you can turn that on in sqlite3. I think SQLite is pretty good for a lot of use cases. An Axum/sqlite CRUD app should be able to handle at least few hundred requests per second on a medium powered box, which is good enough for a lot of things. Postgres is really powerful but I don't think it's actually that common to structure your app around it's unique features.