Is it? Sqlite seems pretty fast. [1]

[1] - https://andersmurphy.com/2025/12/02/100000-tps-over-a-billio...

So if it needs to work offline, but it syncs with a server, then you use both? (And the schema becomes some kind of lowest common denominator?)

I would probably do an event-source architecture, where you record events on the client and then push them to the server when you're reconnected. It has a lot of benefits, for instance, trivial auditing and free serialization.

yeah essentially, see electricsql

though they also have "pglite" running in wasm.

same concept though, sync slices to an embedded db.