Why my CI got 4 minutes faster

Every time I revisit a project after six months, I find at least one place where past-me wrote a comment that present-me has now stopped trusting. Comments rot faster than code.

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.

I keep a small log of decisions in a text file. Not architectural — just small ones. "Picked X over Y because Z." Future me reads it more than I thought he would.