---
name: lean-startup
description: Apply Lean Startup principles for hypothesis validation and iterative product development
version: 1.0.0
author: wondelai (adapted)
platforms: [claude-code, cursor]
license: MIT
source: https://github.com/wondelai/skills
based_on: "The Lean Startup by Eric Ries"
---

# Lean Startup

Apply validated learning to build products customers actually want.

## Scoring System
Rate your product development approach 0-10 on lean principles.
Show: current score → assumptions → experiments → metrics.

## Build-Measure-Learn Loop

```
        Idea
          ↓
        BUILD  ← minimize time to here
          ↓
       Product
          ↓
       MEASURE ← collect actionable metrics
          ↓
         Data
          ↓
        LEARN  ← validate/invalidate hypothesis
          ↓
     Pivot or Persevere
```

**The goal is to minimize the total time through the loop.**

## Hypothesis Types

### Leap-of-Faith Assumptions
Every product is built on assumptions. State them explicitly:
- **Value hypothesis**: Does the product create value for customers?
- **Growth hypothesis**: How will the product spread to new customers?

Format:
```
We believe [target customer] will [do action] because [reason].
We will know this is true when [measurable outcome].
```

## MVP Types (from lowest to highest cost)

| MVP Type | Cost | When to use |
|----------|------|-------------|
| Concierge MVP | Hours | Very early stage, high uncertainty |
| Wizard of Oz | Days | Test demand before building automation |
| Landing page | Days | Validate interest/signups |
| Prototype (Figma) | Days | Validate UX flows |
| Fake door | Days | Test feature demand |
| Functional MVP | Weeks | Validate full value loop |

## Actionable Metrics vs Vanity Metrics

| Vanity | Actionable |
|--------|------------|
| Total registered users | % active users (7-day) |
| Page views | Conversion rate |
| Downloads | Retention D1/D7/D30 |
| Revenue total | Revenue per customer |
| Feature count | Feature adoption rate |

Use **cohort analysis** to see if things are improving over time, not just growing.

## Pivot Types
- **Zoom-in**: a feature becomes the product
- **Zoom-out**: the product becomes a feature of something bigger
- **Customer segment**: same problem, different customer
- **Customer need**: same customer, different problem
- **Platform**: product becomes platform or vice versa
- **Business architecture**: high-margin → high-volume or vice versa

## Pivot or Persevere Decision
Pivot if:
- Experiments are failing to improve metrics
- You're building and building but not learning
- Conversations with customers keep turning to a different problem