Chapter 9

The practices

A practice earns its place in this chapter by being general, which is what admits testing and verification, quality assurance, version control, code review, static analysis and typing, code conventions, dependency management, observability, incident response and hotfixing, and automation – and what cuts formatting into code conventions, infrastructure as code into automation, and feature flags out as a tactic rather than a phase of the pipeline. Each is weighed by the exchange rate of the previous chapter. Testing and verification comes first and carries the most: why to test at all, why test-driven development works in limited cases because exploratory programming has no vision to march towards, why a test is a second and lossy encoding of the same intent, how much testing is enough given the cost of mistakes and the tooling at hand, and how little we can say about whether a test suite is any good.