It's now used by a huge number of developers for running local dev environments, and emulating server products (Google firebase and Prisma both embed it in their CLI). Unit testing postgres backed apps is also made significantly easer with it.

One use case, when doing unit tests, Docker containers, would make it too expensive with many tests. SQLite's type checking is far less strict than Postgres, which would not catch errors that would occur the real database due to type mismatch.

Having something like this, that I can quickly spawn and know, I am getting exact behavior as prod database would be a lifesaver!

Hmm single user website run as HTML from some folder? I guess you could embed this from s3 for multiple users but probably this would be like running multiple engines from the same dir.

I use it for realistic(ish) testing of my hono API, big fan