# Product Lens — Think Before You Build
This lane owns product diagnosis, not implementation-ready specification writing.
If the user needs a durable PRD-to-SRS or capability-contract artifact, hand off to `product-capability`.
When to Use
- Before starting any feature — validate the "why"
- Weekly product review — are we building the right thing?
- When stuck choosing between features
- Before a launch — sanity check the user journey
- When converting a vague idea into a product brief before engineering planning starts
How It Works
Mode 1: Product Diagnostic
Like YC office hours but automated. Asks the hard questions:
``` 1. Who is this for? (specific person, not "developers") 2. What's the pain? (quantify: how often, how bad, what do they do today?) 3. Why now? (what changed that makes this possible/necessary?) 4. What's the 10-star version? (if money/time were unlimited) 5. What's the MVP? (smallest thing that proves the thesis) 6. What's the anti-goal? (what are you explicitly NOT building?) 7. How do you know it's working? (metric, not vibes) ```
Output: a `PRODUCT-BRIEF.md` with answers, risks, and a go/no-go recommendation.
If the result is "yes, build this," the next lane is `product-capability`, not more founder-theater.
Mode 2: Founder Review
Reviews your current project through a founder lens:
``` 1. Read README, CLAUDE.md, package.json, recent commits 2. Infer: what is this trying to be? 3. Score: product-market fit signals (0-10) - Usage growth trajectory - Retention indicators (repeat contributors, return users) - Revenue signals (pricing page, billing code, Stripe integration) - Competitive moat (what's hard to copy?) 4. Identify: the one thing that would 10x this 5. Flag: things you're building that don't matter ```
Mode 3: User Journey Audit
Maps the actual user experience:
``` 1. Clone/install the product as a new user 2. Document every friction point (confusing steps, errors, missing docs) 3. Time each step 4. Compare to competitor onboarding 5. Score: time-to-value (how long until the user gets their first win?) 6. Recommend: top 3 fixes for onboarding ```
Mode 4: Feature Prioritization
When you have 10 ideas and need to pick 2:
``` 1. List all candidate features 2. Score each on: impact (1-5) × confidence (1-5) ÷ effort (1-5) 3. Rank by ICE score 4. Apply constraints: runway, team size, dependencies 5. Output: prioritized roadmap with rationale ```
Output
All modes output actionable docs, not essays. Every recommendation has a specific next step.
Integration
Pair with: - `/browser-qa` to verify the user journey audit findings - `/design-system audit` for visual polish assessment - `/canary-watch` for post-launch monitoring - `product-capability` when the product brief needs to become an implementation-ready capability plan