lean-startup

What this skill does

# Lean Startup Methodology

A systematic approach to building startups and launching new products that shortens development cycles and rapidly discovers if a business model is viable.

## Core Principle

**Entrepreneurship is a form of management.** Success doesn't require a perfect plan or brilliant insight—it requires a systematic process for testing assumptions, learning from customers, and iterating rapidly.

**The foundation:** Most startups fail not because they couldn't build what they planned, but because they built the wrong thing. The Lean Startup methodology applies scientific experimentation to eliminate waste and accelerate validated learning.

## Scoring

**Goal: 10/10.** When reviewing or creating product development plans, experiments, or metrics, rate them 0-10 based on adherence to Lean Startup principles. A 10/10 means full application of Build-Measure-Learn, validated learning, and evidence-based decisions; lower scores indicate waterfall thinking or waste. Always provide the current score and specific improvements needed to reach 10/10.

## The Build-Measure-Learn Loop

The fundamental cycle of Lean Startup:

```
     IDEAS
       ↓
    BUILD → Product
       ↓
    MEASURE → Data
       ↓
    LEARN → Knowledge
       ↓
    (back to IDEAS)
```

**Critical insight:** The loop is actually backward. Start with what you want to learn, determine metrics that will inform that learning, then build the minimum product to collect those metrics.

**Reverse planning:**
1. **What do we want to learn?** (hypothesis to test)
2. **How will we know if we learned it?** (metrics)
3. **What's the minimum we can build?** (MVP)

**Goal:** Minimize total time through the loop.

See: [references/build-measure-learn.md](references/build-measure-learn.md) for detailed loop execution.

## Validated Learning

**Definition:** Learning what customers really want through validated experiments, not opinion or anecdotes.

**Validated learning is not:**
- Building features customers request (they don't know what they want)
- Achieving vanity metrics (downloads, signups without engagement)
- Doing surveys or focus groups (people lie/mispredict behavior)

**Validated learning is:**
- Testing hypotheses with real behavior
- Measuring what customers *do*, not what they *say*
- Running experiments that could falsify your assumptions
- Learning = when your predictions were wrong

**The Validation Ladder:**

| Level | Evidence | Strength |
|-------|----------|----------|
| 1 | "I think customers want this" | Weakest (opinion) |
| 2 | "Customers said they want this" | Weak (stated preference) |
| 3 | "Customers signed up for early access" | Medium (low commitment) |
| 4 | "Customers paid a deposit" | Strong (real commitment) |
| 5 | "Customers are actively using it" | Strongest (revealed preference) |

**Target:** Level 4-5 before building at scale.

## Minimum Viable Product (MVP)

**Definition:** The version of a new product that allows a team to collect the maximum amount of validated learning with the least effort.

**MVP is not:**
- A prototype (not about proving technical feasibility)
- A beta version (not about quality or features)
- A minimum marketable product (it might be embarrassing)

**MVP is:**
- A learning vehicle
- The smallest experiment to test a hypothesis
- Often much smaller than you think

**MVP Types:**

| Type | What It Is | When to Use | Example |
|------|------------|-------------|---------|
| **Concierge** | Manual service pretending to be automated | Test if solution is valuable | Food on the Table (manual meal planning) |
| **Wizard of Oz** | Fake automation, manual backend | Test if automation is needed | Zappos (no inventory, bought shoes retail) |
| **Smoke test** | Landing page + signup, no product | Test demand before building | Dropbox video (explained concept, measured signups) |
| **Single feature** | One core feature only | Test which feature is most valuable | Twitter (just status updates) |
| **Piecemeal** | Combine existing tools | Test workflow before custom build | Groupon (WordPress + email) |

**MVP Design Questions:**
- What's the riskiest assumption to test first?
- What's the minimum to test that assumption?
- How do we measure if the assumption was validated?

**Common mistakes:**
- Building too much (overestimate MVP size)
- Optimizing for scale prematurely
- Confusing quality with learning (MVP can be low quality)
- Skipping the experiment (building without hypothesis)

See: [references/mvp-design.md](references/mvp-design.md) for MVP types and design patterns.

## Leap-of-Faith Assumptions

**Definition:** The assumptions that, if wrong, will cause your business to fail.

**Process:**
1. **Identify your business model's critical assumptions**
2. **Prioritize by risk** (which failure would be fatal?)
3. **Test the riskiest assumption first**

**Common leap-of-faith assumptions:**

| Assumption Type | Question | Test Method |
|----------------|----------|-------------|
| **Value hypothesis** | Do customers care about this problem? | Smoke test, concierge MVP |
| **Growth hypothesis** | How will customers discover us? | Channel tests, referral experiments |
| **Retention hypothesis** | Will customers come back? | Cohort analysis, engagement metrics |
| **Monetization hypothesis** | Will customers pay? | Pre-orders, pricing tests |

**Example: Dropbox**
- **Leap-of-faith:** "People will download and use a file sync tool"
- **Test:** Explainer video showing product (before building full version)
- **Metric:** Beta signup list grew from 5,000 to 75,000 overnight
- **Learning:** Validated demand before building scale infrastructure

**Anti-pattern:** Testing assumptions in order of ease rather than risk.

See: [references/assumptions.md](references/assumptions.md) for assumption mapping frameworks.

## Innovation Accounting

**Definition:** Measuring progress when traditional accounting doesn't apply.

**The problem with traditional metrics:**
- Revenue (startups start at $0)
- Customers (startups start at 0)
- Vanity metrics (look good but don't drive decisions)

**Innovation accounting framework:**

### 1. Establish the Baseline
**Question:** Where are we today?

Measure current reality, even if it's zero or embarrassing.

**Metrics to establish:**
- Conversion funnel (signup → active → retained → paying)
- Engagement (DAU/MAU, session length, features used)
- Economics (CAC, LTV, churn rate)

**Goal:** Know your starting point precisely.

### 2. Tune the Engine
**Question:** What can we improve to move toward our goal?

Run experiments to improve baseline metrics.

**Examples:**
- A/B test pricing ($9/mo vs. $19/mo)
- Test onboarding flows (% who complete setup)
- Experiment with channels (SEO vs. paid vs. referral)

**Goal:** Systematically improve metrics through validated learning.

### 3. Pivot or Persevere
**Question:** Are we making sufficient progress, or do we need to change strategy?

Based on data, decide whether to continue or pivot.

**Criteria:**
- Are metrics moving in the right direction?
- Is the rate of improvement acceptable?
- Are we learning what we expected?

**Goal:** Make evidence-based strategic decisions.

See: [references/innovation-accounting.md](references/innovation-accounting.md) for metric frameworks and dashboards.

## Actionable vs. Vanity Metrics

**Vanity metrics:** Make you feel good but don't change behavior.

**Actionable metrics:** Drive decisions and clarify cause and effect.

| Vanity | Why It's Bad | Actionable Alternative |
|--------|-------------|------------------------|
| **Total signups** | Always goes up, no context | **% signup → active** (conversion rate) |
| **Page views** | Doesn't indicate value | **Time on page**, **bounce rate** |
| **Total users** | Includes inactive/churned | **Active users** (DAU, WAU, MAU) |
| **Downloads** | Doesn't mean usage | **DAU/downloads** (activation rate) |
| **Revenue** | Without context | **Revenue per cohort**, **LTV/CAC** |

**Three