You accept downtime. That's the limitation of SQLite.

Or you use some distributed SQLite tool like rqlite, etc

I'm personally fine with a little bit of downtime for my particular small app. I'm just surprised there's not a more detailed story around deploying sqlite in a high availability prod environment given it's increased popularity and coverage over the last few years. Especially surprising with Rails' (my stack) going full "sqlite-first".

The "sqlite-first" folks have accepted that a bit of downtime is better than engineering wildly complex systems that avoid it, for non-mission-critical apps (if your mission is a low volume e-commerce shop.. it's not critical)