I lost three days of customer data before I realized SQLite's "database is locked" errors were just the symptom. The real disease was silent corruption happening in production.
You've probably deployed SQLite thinking it handles concurrent writes. The documentation says it does. The internet says it does. Hell, even your tests pass. But there's a specific scenario where SQLite will corrupt your database so quietly you won't notice until your backups are also toast.
Everyone tells you to enable Write-Ahead Logging. "It solves concurrency!" they say. Let me show you the code that's probably in your production right now.