A database connection that silently dropped SSL because it trusted the wrong signal.
A stricter-than-reality parameter type is enough to break strict mode.
When the newest major breaks tooling that hasn't caught up yet.
When the vulnerable package isn't in your package.json at all.
Gate publishing on the post date instead of a draft flag you have to remember to change.
A dev server hiccup that looks like a code error but isn't.
Find the commit that deleted a file and bring it back, without touching anything else.
The handful of standing instructions I give every coding agent, and why each one earns its place.
The one-liner for tracking down whatever stole port 3000.