lean-ux

SKILL.md

Lean UX Framework

A practice-driven approach to user experience design that replaces heavy deliverables with rapid experimentation, cross-functional collaboration, and continuous learning. Based on a fundamental truth: teams that obsess over pixel-perfect specs before testing with real users waste months building the wrong thing. Lean UX shifts the question from "What should we design?" to "What do we need to learn?"

Core Principle

Outcomes over outputs. The value of a design is not measured by the fidelity of the deliverable but by the change in user behavior it produces.

The foundation: Traditional UX waterfalls requirements into wireframes, wireframes into mockups, mockups into specs, and specs into code. At every handoff, context is lost and assumptions go untested. Lean UX eliminates waste by compressing the distance between idea and evidence. Instead of debating opinions in conference rooms, teams declare assumptions, form hypotheses, run the smallest possible experiment, and let real user behavior settle the argument. Shared understanding replaces documentation. Learning velocity replaces pixel perfection.

Scoring

Goal: 10/10. When reviewing or creating UX processes, design plans, or team workflows, rate them 0-10 based on adherence to Lean UX principles. A 10/10 means full alignment with hypothesis-driven design, minimal deliverables, collaborative practices, and outcome-focused metrics; lower scores indicate heavy-deliverable thinking or untested assumptions. Always provide the current score and specific improvements needed to reach 10/10.

1. Declaring Assumptions

Core concept: Every design starts with assumptions. Lean UX makes those assumptions explicit so they can be prioritized and tested, rather than baked invisibly into specifications.

Why it works: When assumptions remain unspoken, teams build on shaky ground and discover problems only after launch. By surfacing assumptions early, the team can focus energy on the riskiest ones first, reducing the cost of being wrong.