---
name: product-lens
description: Validate the 'why' before building. Run product diagnostics, pressure-test product direction, and prevent building the wrong thing. Use when starting a feature, doing product review, choosing between features, before a launch, or converting a vague idea into a product brief.
---

# Product Lens — Think Before You Build

This skill owns product diagnosis, not implementation specification.

## 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
- Converting a vague idea into a product brief

## Mode 1: Product Diagnostic

Ask the hard questions (like YC office hours):

1. **Who is this for?** — specific person, not "developers"
2. **What's the pain?** — 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 with answers, risks, and go/no-go recommendation.

## Mode 2: Founder Review

Review current project through a founder lens:

1. Read project files, README, recent work
2. Infer: what is this trying to be?
3. Score product-market fit signals (0-10):
   - Usage growth trajectory
   - Retention indicators
   - Revenue signals
   - Competitive moat (what's hard to copy?)
4. Identify: the one thing that would 10x this
5. Flag: things being built that don't matter

## Mode 3: User Journey Audit

Map the actual user experience:

1. First touch — how do they discover this?
2. First value — how fast do they get value?
3. Habit loop — what brings them back?
4. Expansion — how do they get more value over time?
5. Friction points — where do they get stuck or leave?

## Mode 4: Feature Prioritization

When choosing between features, score each on:

| Criteria | Weight | Score (1-10) |
|----------|--------|--------------|
| User pain severity | 30% | |
| Implementation effort | 25% | |
| Strategic alignment | 20% | |
| Revenue impact | 15% | |
| Technical debt reduction | 10% | |

Rank by weighted score. Build the highest-scoring feature first.

## Guardrails

- Never skip the "why" and jump to "how"
- If the answer to "who is this for?" is vague, STOP and clarify
- A feature without a measurable success metric is not ready to build
- Prefer removing features over adding them