Spec-Driven Development

Spec-driven development means writing a detailed specification before letting an agent write code, giving the agent explicit success criteria, constraints, edge cases, and architectural context instead of a vague natural language request. The gap between "build me a login page" and a structured spec that defines auth flow, error states, styling conventions, and API contracts is the gap between throwaway code and production-ready output. A spec also becomes a natural review artifact: comparing the implementation against the written spec makes code review faster and more focused than reading code with no declared intent.