Spec Driven Development: Build With AI Without Losing Control

Vibe coding works for the first few weeks. The problem starts when it stops working.Week 1: The agent builds fast. Everything flows.Week 3: You change one thing. Something else breaks.Week 4: The agent no longer remembers what you decided.Week 5: You spend more time explaining the project's state than receiving code.The problem isn't the model. It's that there is no artifact telling the agent what is being built, why, and what must be true once it’s finished. Without that, the agent fills in the blanks. Its inventions are good. But they aren't yours.Spec-Driven Development (SDD) is the solution.SDD is a workflow where the spec exists before the agent starts. The spec describes the expected behavior. The agent implements it. When it's done, you verify if what was built matches what you specified. Not by "eye-balling" it, but with concrete criteria.What you’ll find in this book:The Problem — Why vibe coding has a ceiling and exactly what causes it.The Method — The 7 phases of SDD: how to write a 500-word PRD, how to break it down into executable issues, and how to close the loop with real QA.The Tools — GitHub SpecKit, openSpec for existing projects, and agnostic workflows (Ralph, GSD, BMAD).In Practice — Greenfield and brownfield projects, the 5 anti-patterns that destroy a spec, and how to adopt SDD as a team.Plus 4 appendices with ready-to-use templates: PRD, constitution, quality checklist, and glossary.16 chapters. No fluff. Featuring real examples of specs that actually worked.Who this book is for: Developers working with AI agents (Claude Code, Cursor, Copilot, Windsurf) who want the output to be predictable, verifiable, and maintainable weeks after they started.Notas de la traducción (Glossary & Nuances):Vibe coding: Se mantiene el término original ya que es un concepto propio de la cultura tech actual.Artifact: Es la palabra técnica precisa en inglés para "artefacto" (documentos, diagramas o modelos que quedan tras un proceso).Greenfield / Brownfield: Son los términos estándar en ingeniería de software para proyectos desde cero y proyectos sobre código existente, respectivamente.No fluff: La mejor traducción para "sin relleno", muy común en marketing de libros técnicos en inglés.Eye-balling it: He usado este modismo para traducir "no a ojo", ya que es muy común entre desarrolladores para referirse a revisar algo de forma superficial sin pruebas automáticas. Read more