Test-driven development
Where the behavior is testable, we write the test first and let it drive the implementation, so the test suite grows with the code instead of being bolted on at the end. This keeps the design honest and gives us a fast signal when a change breaks something. We are pragmatic about it: not every line gets a unit test, but the core logic and the parts that are expensive to get wrong do.
- Test first on core logic
- Suite grows with the code
- Fast signal on regressions