lean-startup

What the source does

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Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha 5015fcf4cde3 · 27 Oct 2026Report an issue or request a re-scan

• Publishergetagentseal GitHub organizationOwner of the repository this skill is read from
• Source foldergetagentseal/founder-playbook/skills/lean-startupThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdict5015fcf4cde3A new audit runs when the source changes
• Repository statusNot archivedLast push 20 days ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Applies Eric Ries's Lean Startup methodology for building products under extreme uncertainty. Use when iterating toward product/market fit, designing MVPs, deciding whether to pivot or persevere, setting up actionable…

---
name: lean-startup
description: "Applies Eric Ries's Lean Startup methodology for building products under extreme uncertainty. Use when iterating toward product/market fit, designing MVPs, deciding whether to pivot or persevere, setting up actionable metrics, or accelerating the Build-Measure-Learn loop. Triggers include 'how do we test this idea fast', 'what should our MVP look like', 'our metrics look good but we're not growing', 'should we pivot', 'we're building features no one uses', 'how do we measure validated learning', 'vanity metrics vs real metrics', 'how to do innovation accounting'. NOT for companies with proven product/market fit scaling a known playbook (use Crossing the Chasm), not for determining Market Type (use Four Steps), not for sales methodology (use SPIN Selling), not for pricing strategy (use Monetizing Innovation)."
---

> **Note:** This skill is independent analysis and commentary, not a reproduction of the original text. It synthesizes the book's core ideas with modern startup practice, surfaces where frameworks are outdated or incomplete, and integrates perspectives from adjacent disciplines. For the full argument and context, read the original book.


# The Lean Startup

> "The Lean Startup is not a collection of individual tactics. It is a principled approach to new product development." - Eric Ries

## Should You Use This Skill?

```
Are you building something under conditions of extreme uncertainty?
|-- YES --> Do you know who your customers are?
|   |-- NO  --> Start with Four Steps (Customer Discovery), use Lean
|   |           Startup for iteration speed within that process
|   +-- YES --> Do you have product/market fit?
|               |-- NO  --> THIS SKILL. Build-Measure-Learn loop.
|               +-- YES --> Use Crossing the Chasm for mainstream scaling
+-- NO  --> Are you optimizing an existing product in a known market?
            |-- YES --> Lean Startup principles apply (small batches,
            |           Five Whys) but you don't need the full framework
            +-- NO  --> Rethink what you're doing
```

---

## The Core Insight

**Most startups fail not because they can't build a product, but because they build something nobody wants.** The default response to failure is: we didn't plan well enough, execute hard enough, or have the right vision. Ries argues the real problem is the absence of a management framework designed for uncertainty.

A startup is: **a human institution designed to create a new product or service under conditions of extreme uncertainty.** This definition applies to garage founders, corporate intrapreneurs, and government innovators alike.

### The Five Principles

1. **Entrepreneurs are everywhere** - any organization creating under uncertainty
2. **Entrepreneurship is management** - not just "a cool product" but a discipline
3. **Validated learning** - not "we learned a lot" but learning backed by empirical data
4. **Build-Measure-Learn** - turn ideas into products, measure response, learn whether to pivot or persevere
5. **Innovation accounting** - hold innovators accountable with a new kind of accounting designed for uncertainty

---

## Build-Measure-Learn

The fundamental activity loop. **Minimize total time through the loop.**

```
         IDEAS
        /      \
       /        \
  LEARN          BUILD
      \          /
       \        /
        DATA--PRODUCT
        (Measure)
```

**Critical insight:** Although the loop reads Build-Measure-Learn, you **plan in reverse**: figure out what you need to LEARN, determine what DATA will tell you that, then BUILD only what's needed to get that data.

> "We need to focus our energies on minimizing the TOTAL time through this loop."

### Leap-of-Faith Assumptions

Every startup rests on two untested assumptions:

| Assumption | Question | How to Test |
|---|---|---|
| **Value hypothesis** | Does the product deliver value to customers who use it? | Engagement, retention, willingness to pay |
| **Growth hypothesis** | How will new customers discover the product? | Viral coefficient, referral rates, word-of-mouth tracking |

Both must be tested empirically, not assumed. Use **analogs** (similar successes) and **antilogs** (similar failures) to sharpen assumptions before testing.

> "The two most important assumptions are the value hypothesis and the growth hypothesis."

---

## Minimum Viable Product (MVP)

The MVP is the **fastest way to get through the Build-Measure-Learn loop with minimum effort.** It is NOT the smallest product. It is the smallest experiment that tests your leap-of-faith assumptions.

```
WHAT AN MVP IS:                    WHAT AN MVP IS NOT:
- A learning vehicle               - A crappy v1.0
- Tests one specific assumption    - The smallest feature set
- Designed to maximize learning    - A prototype to show investors
- May lack features, polish, UX    - A proof of concept
- Can be embarrassingly simple     - A demo
```

### MVP Types

| Type | When to Use | Example |
|---|---|---|
| **Video** | Value prop is hard to explain; gauge demand before building | Dropbox: 3-min demo video, signups went 5K to 75K overnight |
| **Concierge** | Deliver the value manually to one customer at a time | Food on the Table: CEO personally picked recipes and shopped for one family |
| **Wizard of Oz** | Automate the frontend, manual backend | Zappos: photos of shoes from stores, bought and shipped when ordered |
| **Single-feature** | Test one value driver with real usage | Groupon: WordPress blog + email, one deal per day in one city |
| **Smoke test** | Gauge demand before building anything | Landing page + signup form, measure conversion |

### MVP Quality Concerns

> "If we do not know who the customer is, we do not know what quality is."

Customers don't care about quality dimensions you're imagining. Build the MVP, ship it, and let customer behavior (not opinions) tell you what quality means.

---

## Innovation Accounting

Traditional accounting can't

Excerpt, first 6,000 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/getagentseal/founder-playbook
git -C founder-playbook checkout 5015fcf4cde3

Works in

1. 2026-10-27
   ✓SAFE B 89 / 100

   first audit · source 5015fcf4cde3

Questions about lean-startup

• github.com/getagentseal/founder-playbook/tree/main/skills/lean-s — the audited source at commit 5015fcf4cde3 and every finding aboveObserved · 27 Oct 2026

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