Spec-Driven Development

Overview

Most AI coding failures happen because the agent starts coding before understanding the problem. Spec-driven development reverses the flow: first write a detailed specification that describes what to build, why, and how — then validate the spec — then implement. The spec becomes both the contract and the test oracle.

When to Use

• Starting a new feature and want to think before coding
• Building something complex where wrong assumptions are expensive
• Working in a team where others need to review the design before implementation
• The agent keeps building the wrong thing because requirements are ambiguous
• Creating RFCs or architecture decision records (ADRs) for the team

Instructions

The Spec-First Workflow