Flaky tests aren't a coincidence. They're a symptom of timing assumptions you didn't know you made. Here's how I find and fix them.

Patterns I underestimated for too long, and the cases where each one earns its place in the codebase.

What I learned splitting my time between shipping features and breaking them on purpose.

An honest comparison after using both in production for two years.

A handful of small utility types that paid for themselves within a week.