I Use Development-Driven Specs, Not Spec-Driven Development

The article describes "Ensemble," a coding agent built using a development-driven approach where specifications and code are built together through pair-programming with AI, rather than writing detailed specs upfront. The methodology emphasizes learning and recording design decisions, lessons, and tradeoffs during implementation, then documenting these insights to create an executable specification that can transfer expertise to other agents. This approach prioritizes teaching how and why systems are built over merely listing desired features, with the reusable asset being the knowledge needed to reconstruct the implementation.