On-call handoff notes that people actually read

We used to write long handoff documents that nobody read. Now we write three lines and people actually use them.

The template:

1. What's on fire (or nothing)
2. What I changed that you should know about
3. What I'm worried about

That's it. Three lines, posted in the on-call channel at handoff.

The surprising part: the third line is the most valuable. "I'm worried about the cron job that runs at 3am" has saved us several times.

We also added a rule: if you had a quiet week, say so explicitly. Silence is ambiguous; "nothing happened" is information.

Side quest: reading SQLite internals. WAL mode is a great case study in making a simple thing predictable.