Spec-driven development

Spec-driven Development (SDD) makes the specification the central artefact of development. Requirements, architecture and constraints are captured in a versioned document that evolves alongside the code and serves as a reference for both developers and Coding Agents. Discussions about behaviour and design take place before implementation, and the generated code is guided by precise specifications rather than assumptions.

The specifications also record the intentions behind past changes—information that is difficult to reconstruct from commit messages or code alone. Tools such as OpenSpec structure the workflow into proposals, specifications, design decisions and tasks. We are evaluating SDD as a complement to Agentic Engineering.