Months of static analysis, two real bugs

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.

Latency budgets work better than latency targets. Targets are aspirational. Budgets force you to delete features when you go over.

The team I learned the most from didn't have great tools. They had a great habit of reading each other's pull requests in full, including the parts that weren't theirs.

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.