Numbers I check before merging

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 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.

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.

Most of the trouble I see in production comes from boundary cases someone promised would never happen. The code is fine. The plan is fine. The promise is what ages badly.

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.

I trust monorepos more in the second year than I did in the first. Most of the early friction goes away once the tooling catches up.