Lean UX
Collaborative, experiment-driven UX design
Practice collaborative, experiment-driven UX design using Jeff Gothelf and Josh Seiden's Lean UX methodology. This skill equips your AI agent with hypothesis-driven design, cross-functional collaboration techniques, and MVPs for validating UX decisions with real users.
This skill is compatible with Claude, Claude Code, Claude Cowork, Codex, Cursor, OpenClaw, Hermes Agent, and other agentskills.io-compatible agents.
What is the Lean UX skill?
Lean UX moves design from deliverables to experiments, applying Jeff Gothelf and Josh Seiden’s book of the same name. The skill has your agent restate a feature request as a testable hypothesis — we believe this change produces that outcome, and we will know when this metric moves — then design the smallest thing that could disprove it.
Key concepts from Lean UX your agent applies
Hypothesis-Driven Design
Frame design decisions as hypotheses: "We believe [this change] will result in [this outcome]. We'll know we're right when [this metric changes]."
Outcomes over Outputs
Focus on changing customer behavior (outcomes), not shipping features (outputs). Measure success by impact, not delivery.
Cross-Functional Collaboration
Break down silos between design, engineering, and product. Co-create solutions with shared understanding.
Design Studio Method
Run collaborative sketching sessions where the whole team generates and critiques ideas together.
Minimum Viable Product
Design the smallest experiment that tests your riskiest assumption — a landing page, Wizard of Oz test, or concierge MVP.
When to use Lean UX — and when not to
Reach for it when
- Your roadmap is a list of features with no statement of what any should change.
- Design hands over comps, engineering builds them, and nobody checks whether the outcome arrived.
- Stakeholders argue about the solution because the assumption underneath it was never written down.
- You want to test a redesign before committing a quarter to building it.
Reach for something else when
- You need interview technique that stops users being polite — The Mom Test is the sharper tool.
- You want a weekly discovery rhythm and opportunity solution trees — Continuous Discovery goes deeper.
- The business model is unproven, not just this screen — Lean Startup operates at that altitude.
- You want a tested prototype by Friday — Design Sprint is the packaged five-day version.
Example prompts for the Lean UX skill
Frame this feature idea as a Lean UX hypothesis with measurable outcomes using lean-ux skill
Product designPlan a design studio session for our cross-functional team using lean-ux skill
CollaborationDesign a minimum viable experiment to test our onboarding redesign using lean-ux skill
ExperimentationShift our team from output-based to outcome-based success metrics using lean-ux skill
Team processLean UX vs the other Design & UX skills
All 9 Design & UX skills are free and install the same way — the only question is which framework fits the job in front of you.
| Skill | Based on | Best for |
|---|---|---|
| Refactoring UI | Refactoring UI — Adam Wathan & Steve Schoger | Practical UI design system |
| iOS HIG Design | Human Interface Guidelines — Apple | Native iOS app design guidelines |
| UX Heuristics | Don’t Make Me Think — Steve Krug & Jakob Nielsen | Usability evaluation and principles |
| Web Typography | On Web Typography — Jason Santa Maria | Web typography principles and implementation |
| Design of Everyday Things | The Design of Everyday Things — Don Norman | Foundational design principles: affordances, signifiers, feedback |
| Top Design | Elite Agency Techniques — Locomotive, Studio Freight, AREA 17 | Award-winning 10/10 web design |
| Lean UX | Lean UX — Jeff Gothelf & Josh Seiden | Collaborative, experiment-driven UX design |
| Microinteractions | Microinteractions — Dan Saffer | Designing details that delight users |
| Steve Jobs Design Review | Steve Jobs — Walter Isaacson | Jobs-style reviews: ruthless simplicity, focus, binary verdicts |
Frequently asked questions
How do I install the Lean UX skill?
Run npx skills add wondelai/skills/lean-ux --global. It takes about 30 seconds and needs no account. The Lean UX skill then works in Claude, Claude Code, Claude Cowork, Codex, Cursor, OpenClaw and Hermes Agent — anything that reads the open agentskills.io format — and your agent loads it on its own when a task calls for it. It is free and MIT-licensed, and the source is at https://github.com/wondelai/skills.
Which book is the Lean UX skill based on?
It packages Lean UX by Jeff Gothelf & Josh Seiden — lean UX pioneers, bestselling authors and product coaches. The skill distils the book's method into instructions your agent follows while it works, covering hypothesis-driven design, outcomes over outputs and cross-functional collaboration. It sits in the Design & UX part of the library.
How is it different from the Lean Startup skill?
Same loop, different altitude. Ries is testing whether the business should exist — the unit of learning is a pivot or a persevere, and the experiment might be a fake landing page for a product with no code behind it. Lean UX runs inside a team that already has a product, testing design decisions: this flow, this onboarding step, this navigation model. If you are questioning the company, use Lean Startup. If you are questioning the screen, use this.
Half the book is about cross-functional teams. Does it help a solo builder?
The collaboration chapters are largely moot when you are one person and an agent — there are no silos to break and design studio with a single participant is just sketching. What survives is most of the value: writing the assumption down before you build, framing it as a hypothesis with a named metric, and picking the smallest test that could kill it. Solo founders skip this discipline most, so it pays off disproportionately.
Do I need experiment infrastructure to run this?
No, and assuming you do is what stops teams starting. Most of the MVPs here are qualitative and cheap: a landing page that measures intent, a Wizard of Oz test where a human does the work the feature will eventually do, a concierge version for five customers. Statistical testing only earns its place once you have the traffic for it. Until then, five users watching a prototype answers the question faster.
Isn’t “outcomes over outputs” just a slogan?
It becomes one the moment you cannot name the metric. The skill is deliberately strict here — if the hypothesis ends in “users will be more engaged” with nothing instrumented behind it, you have written a wish, not an experiment. Being forced to specify what would change, by how much, and where you would see it is most of the value; a fair number of feature ideas do not survive that sentence.
Guides that use this skill
Install Lean UX
Free, open-source, and ready in 30 seconds.
npx skills add wondelai/skills/lean-ux --global MIT Licensed · Works with Claude, Claude Code, Claude Cowork, Codex, Cursor, OpenClaw, Hermes Agent & other agentskills.io agents · No account needed
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