Articles
- 7 min read
The Direction of a Dependency Matters More Than Its Existence
A dependency between two pieces of code is never symmetric — one side breaks when the other changes. Pointing it at the right side is the entire discipline.
- 5 min read
Case File: Migrating a Legacy Reservation Handler Without a Rewrite
A tangled legacy handler gets pulled apart one bounded step at a time, behind the safety net the earlier testing series already built.
- 7 min read
Testing a Legacy Project From Scratch With an AI Agent
Most engineers already use AI to write code. Here's how to sequence an agent through testing a legacy codebase, without doing it all in one big step.
- 6 min read
A Testing Strategy for a Codebase With No Tests
A codebase with no tests doesn't need unit tests for new features first. It needs an end-to-end net at the points where the business is most fragile.
- 2 min read
The First Test I'd Write in a File With None
I didn't choose my first test — a production incident chose it for me. What that taught me about testing the highest-risk behavior first.