A/B Testing

This skill provides the complete lifecycle for production A/B testing of design variants. Variants are real, production-quality code — not mockups.

Lifecycle

CREATE (/design) → DEPLOY (trunk + flags) → MEASURE (analytics) → DECIDE (/ab-decide) → CLEANUP (/ab-cleanup)

1. CREATE

/blueprint-dev:bp:design uses the design-variant-generator to create 2-3 real component variants, the design-critic to evaluate them, and the ab-test-engineer to wire up flags and tracking.

2. DEPLOY

Variants ship to trunk behind feature flags. Compatible with trunk-based development — no long-lived branches needed.

3. MEASURE

Analytics tracking fires at key interaction points. Users monitor their analytics dashboard for results.

4. DECIDE

/blueprint-dev:bp:ab-decide uses the design-decision-analyst to interpret results and recommend a winner based on statistical significance.

5. CLEANUP

/blueprint-dev:bp:ab-cleanup follows the decision document's cleanup plan to remove the losing variant, promote the winner, and clean up flags/tracking.

Key Principles

• Meaningful differences: Variants must differ in layout, interaction, hierarchy, density, or navigation — not just cosmetics
• Statistical rigor: p < 0.05, 80% power, calculated sample sizes
• Guardrail metrics: Tests auto-stop if critical metrics degrade
• Clean cleanup: Every test ends with a clean codebase — no lingering dead code

References

• references/tracking-plan-template.md — Template for tracking plans
• references/code-templates.md — Stack-specific code templates for wrappers, flags, and tracking