Why my CI got 4 minutes faster

If a config file has more than a dozen options, half of them aren't being used. The other half are being used in ways the original author didn't predict.

I write smaller commits than I used to. The commits are uglier in isolation and much easier to read in sequence.

There's a kind of premature optimization that comes from imagining a future team. "What if someone needs to swap this out?" Often, no one does.

When a system surprises me, my first instinct used to be to fix the surprise. Now my first instinct is to figure out which mental model of mine was wrong, and update that.

The fastest debugging trick I've learned is to write out, in one sentence, what the system is supposed to be doing. Half the time I notice the bug while writing the sentence.