What to do about SQLITE_BUSY errors despite setting a timeout - Bert Hubert's writings

The tl;dr on this, to prevent SQLITE_BUSY errors even when setting a timeout, don’t ever upgrade transactions to read-write. If you know you are going to write in a transaction, use ‘BEGIN IMMEDIATE’, or start off with the write. But do read on for why this is so, and how other databases struggle with this problem as well.