Spec-driven development (SDD) is the practice of writing a specification so detailed, unambiguous, and complete that an AI coding agent can implement it with zero human clarification. I run a product team built entirely on this idea: I write the specs, agents write the software, and a human still reviews every merge. The essays below are field reports from that work, in reading order, with the caveats left in. The six operating principles underneath the practice are on the expertise page.

The first posts in this series are on the way.