engineering-lifecycle

A TDD-driven lifecycle guides software projects by enforcing structured phases, quality gates, and execution routing across features. It reduces drift and ensures disciplined delivery from planning through verification.

The RED GREEN REFACTOR cycle is a TDD implementation pattern where you write a failing test, write code to pass it, then refactor. This Skill enforces this cycle for each task to maintain code quality throughout the software lifecycle.

To plan new software features, use the plan creation command to define tasks and milestones in a PLAN.md file. This structures the work before entering the TDD cycle and running quality gates for verification.

To verify software feature completion, run the six quality gates for comprehensive checks or use a quick check command for faster validation. These gates enforce 80%+ test coverage and ensure multi-phase verification.

This TDD lifecycle approach works for both new initiatives and ongoing software work. You can use execution routing to run defined phases on existing projects, applying the same TDD cycles and quality gates for continuous discipline.

A limitation of a TDD-driven software lifecycle is the strict discipline required; every feature must pass through PLAN.md creation, full TDD cycles, and six quality gates. This overhead may slow down rapid prototyping where verification is not yet critical.