Here are a few other sources I googled:
https://www.sqlite.org/famous.html
This is the best I can do, because I have no idea what else you want. If I had the time, I could throw up a simulated million users doing a TODO app with SQLite as the backing DB engine, but I don't have time, I have a 2 year old. Do your own research from here, or don't and just use Postgres until you retire, I don't really care that much.
I don’t think your example is a good fit for SQLite as it’s not a good fit for any sql store that I know of.
https://www.uber.com/blog/building-ubers-fulfillment-platfor...
The parent asked about use cases where there wasn’t an _external_ (which I interpret to mean “handled explicitly by the app, not the database”) sharding / caching layer.
Spanner internally handles splits based on load / size.
That having been said, more careful reading of the Uber post shows that they still do employ additional app-level explicit sharding to resolve hot-spots, so it’s probably a fair point that this doesn’t qualify as an example the parent was looking for.
Legitimately interested as this is something I have more than a little professional interest.
That said, “show me an app doing 5k concurrent writes with SQLite” seems like a much more reasonable standard.
sigh. any app based on SQLite with more than 1 million concurrent users, 75% reads.