Spec-Driven Development: Slowing Down to Ship Faster

For a while, AI coding tools made me feel productive in a way that worried me. I'd describe a feature, get 200 lines of code in 30 seconds, skim it, ship it. A week later I'd be back fixing the edge cases I never thought about, because the model didn't either. That's the gap Spec-Driven Development (SDD) fills. What it actually is Write the spec first. Code second. The spec defines goals, constraints, edge cases, and acceptance criteria, and it becomes the source of truth that AI agents (and hum