Quiet UIs and loud bugs

Caches solve a problem and create three new ones: invalidation, observability, and the slow drift between what the cache thinks is true and what the source thinks is true.

I used to add a layer of abstraction the first time I saw a pattern repeat. Now I wait for the third. The waiting is uncomfortable, but the abstractions that survive that wait tend to last.

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.

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