patterns-vertical-tdd

Vertical slice planning transforms user stories into independent, testable cycles with clear boundaries. Each cycle provides explicit task formats, file paths, and verification checkpoints to ensure observable, verifiable progress for test-first development.

A vertical slice is an independent, fully testable work increment that delivers observable value end-to-end. You need vertical slicing when teams struggle to translate vague user needs into concrete, demonstrable software increments.

Apply TDD cycles by mapping user stories to foundation and feature cycles with standardized templates. The workflow enforces red/green/refactor discipline at the task level, ensuring traceability from spec to implementation through verification checkpoints.

Yes, the approach supports end-to-end planning from foundation to feature cycles. It maps each story to independent cycles with standardized templates, task numbering, and documentation standards to ensure consistent practice across teams.

Ensure traceability by using standardized cycle templates with explicit acceptance criteria and verification checkpoints. This enforces test-first discipline and provides task numbering and documentation standards for observable progress.

Avoid vertical slicing when work cannot be decomposed into independent, testable cycles or when delivering observable value in small increments is not a project requirement.