Scenario - Add a Feature

Use this workflow when you are adding new behavior and want predictable delivery instead of one-shot generation.

Outcome

Ship new functionality that meets explicit acceptance criteria and passes staged verification.

Inputs You Need

• a short spec (spec.md or equivalent)
• acceptance criteria and non-goals
• constraints (performance, privacy, compatibility)

Prompt Shape

Read `spec.md` and restate requirements, constraints, and open questions.
Propose an implementation plan before coding.

Implement in slices:
1) data/schema
2) core logic
3) tests
4) integration/UI
5) docs

After each slice, run relevant checks and report results.
Do not proceed to the next slice until current checks pass.

Context Pack Strategy

Include:

• spec with acceptance criteria
• files that define existing patterns for the feature area
• integration boundaries (API contracts, component interfaces)

Exclude:

• low-relevance files not touched by the plan
• broad tool or model comparisons
• old prompt drafts that conflict with the current spec

Verification Loop

1. Confirm requirements and unresolved questions first.
2. Implement one slice at a time.
3. Run checks per slice (tests, typecheck, lint, build as needed).
4. Update spec or plan when scope changes.
5. Run final end-to-end checks before handoff.

Common Failure Mode

Failure mode: skipping planning causes hidden assumptions and rework late in the task.

Recovery move: stop implementation, update spec and acceptance criteria, then resume with a fresh slice plan.

Done Criteria

• all acceptance criteria are satisfied
• non-goals remain untouched
• checks pass at slice level and final integration level
• spec and implementation are aligned

Evidence Status

• Research-backed: verification and human review loops improve downstream quality.
• Practitioner-backed: spec-first workflow reduces ambiguity and drift on larger tasks.

This slice sequence and gating pattern are editorial guidance based on those patterns.

Next Scenario

• Scenario - Safe Refactor