> SQLite has concurrent writes now

Just to clarify: Unless I've missed something, this is only with WAL mode and concurrent reads at the same time as writes, I don't think it can handle multiple concurrent writes at the same time?

As I understand it, there can be concurrent writes as long as they don't touch the same data (the same file system pages, to be exact). Also, the actual COMMIT part is still serialized and you need to begin your transactions with BEGIN CONCURRENT. If two transactions do conflict, the later one will be forced to ROLLBACK although you can still try again. It is up to the application to do this.

See also https://www.sqlite.org/src/doc/begin-concurrent/doc/begin_co...

This type of limitation is exactly why I would recommend "normal" server-based databases like Postgres or MySQL for the vast majority of web backends.

I think only Turso — SQLite rewritten in Rust — supports that.