Spec-Driven Development: From Specs to Code with AI Agents - Simon Martinelli

Start your development process with a blueprint. Most teams jump into coding and leave documentation for later, if at all. Too often this leads to maintenance issues, stalled modernization, and poor business alignment. Spec-driven development flips the order: the specification becomes the single source of truth that drives code, tests, and validation.

This pocket guide introduces the AI Unified Process, a lightweight framework that makes Spec-driven development practical in the age of generative AI. It shows how specs (requirements, use cases, entity models) can act as contracts, enabling AI agents and modern tools to generate, validate, and evolve software with far less guesswork.

Designed for busy teams, this book focuses on the principles of spec-first development, with AI Unified Process skills and templates as the primary enabler. It also introduces emerging tools like Amazon Kiro and GitHub Spec Kit for context. Alongside practical methodology, you’ll work through a hands-on case study that takes you from requirements to executable code. By the end, you’ll understand how to apply Spec-driven Development in practice, avoid common pitfalls, and integrate AI into a disciplined, scalable workflow.

What You Will Learn

Who this Book is for: 
Software developers, tech leads, and architects with basic programming knowledge. No prior experience with requirements engineering or AI tools is required.