implementation-plan

## Purpose Produce an implementation plan that sequences the technical build of a project into ordered phases, driven by dependency rather than preference, with an explicit Definition of Ready and Definition of Done for each phase. **Build order is a technical decision with real consequences, not a scheduling afterthought.** Building a feature before its data foundation exists means rework; building the UI before the API contract is frozen means integration churn. This document exists so those decisions are made once, deliberately, instead of discovered mid-build. ## Input **Works best with:** The project or system name, plus its architecture and/or requirements if they exist. **Also valuable:** The system-architecture-document, technical-specification, and project-plan for this project if already written - this skill sequences their contents rather than re-deriving them. **Example invocation:** `Create an implementation plan for our new marketplace platform. We have the architecture doc (Next.js frontend, Node/Postgres backend, Stripe Connect for payouts) and the technical spec. Sequence the build so an AI coding agent could execute it phase by phase without needing to ask what to build next.` ## Key Concepts ### Foundation Before Features Certain components block almost everything else and must be built first regardless of what feels most important to stakeholders: data model/schema, authentication and authorization, core API scaffolding, CI/CD and environment setup....