How do we build effective test suites at scale?

The Question

How do we build effective test suites at scale - tests that not only ensure correctness but that tell stories, build documentation, and encourage other contributors to write more tests?

Why It Matters

Test suites in large projects often become maintenance burdens rather than assets. When tests are hard to read, hard to write, or disconnected from the code they protect, developers stop writing them. The goal isn’t just coverage - it’s creating a testing culture that compounds over time.

Current Thinking

Effective test suites need to serve multiple purposes:

1. Correctness - The obvious one, catching regressions
2. Documentation - Tests as executable specifications
3. Onboarding - New contributors learn by reading and writing tests
4. Confidence - Enabling refactoring without fear

The key insight: tests should be easier to write than to skip.

Open Subquestions

• How do we make test infrastructure so good that writing tests is the path of least resistance?
• What patterns make tests readable as documentation?
• How do we balance integration vs unit testing in large systems?
• How do we measure test suite health beyond coverage metrics?