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Growth Experimentation

OrganizationPopular
RefoundAI
growth-experimentation

Help users build and scale a high-velocity growth experimentation engine that prioritizes impact and fosters a culture of rapid learning.

Overview

PublisherRefoundAI
Repositorylenny-skills
Skill namegrowth-experimentation
Stars
1.3K
Forks
170
Bundled files
2
LicenseMIT
Links
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • 2 bundled files

    Scripts, templates, and references the model can read while it works. Files are read-only and never executed.

  • Open source

    Published by RefoundAI on GitHub. Read the source before you install it.

Installation

Install the Growth Experimentation AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/RefoundAI/lenny-skills.git /tmp/lenny-skills
mkdir -p .claude/skills
cp -r /tmp/lenny-skills/skills/growth-experimentation .claude/skills/growth-experimentation
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Growth Experimentation in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Growth Experimentation on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Growth Experimentation is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Growth Experimentation Velocity

Build a high-output engine to compound small wins into massive growth.

Help the user with growth experimentation velocity using insights from 10 guests and posts across Lenny's Podcast and Newsletter.

How to Help

  1. Establish the Baseline - Analyze current conversion funnels and identify the single North Star metric to focus on.
  2. Prioritize and Plan - Use frameworks like ICE or RICE to rank experiments by impact and engineering cost.
  3. Execute and Iterate - Launch scrappy tests quickly to find signals of life before scaling into robust features.
  4. Scale and Socialize - Systematize the sharing of wins and failures across the organization to multiply the impact of every insight.

Core Principles

Search for signs of life

Timothy Davis: "You can always do a very, very small test. You can just put a little money into a platform, see if there's a sign of life. If there is, then you can pull back and say, 'Okay, we have signs of life. Now let's build a campaign around that.'"

Validate new channels or ideas using low-budget tests and narrow match thresholds before committing significant resources.

Embrace the counterfactual

From "How today’s top consumer brands measure marketing’s impact": "Testing/conversion lift studies (CLS): regularly run by marketers to validate what performance would look like if you switched a channel off, or scaled spend up or down."

Use randomized testing and lift studies as the gold standard to observe what would happen without your intervention.

Leverage compounding effects

From "The secret to Duolingo’s exponential growth": "To get the best long-term gains, you should always have a sense of urgency. The quicker you launch winning experiments, the quicker those changes impact your growth. Not only that, but these improvements compound!"

Focus on high experiment velocity because early small wins multiply over time into significant competitive advantages.

Optimize psychological commitment

Jackson Shuttleworth: "We've actually set up really good infrastructure for copy testing. We used to say continue, our standard CTA is continue, and we changed that to commit to my goal, and it was a massive win."

Shift from generic microcopy to intentional language that reinforces the user's specific goals and psychological state.

Lower friction with scrappy tools

From "Fostering a culture of experimentation": "When systems are still in flux, you don't want to overinvest in tooling that will become outdated immediately when your data schema gets updated or some other piece of infrastructure changes. However, it is essential to have a way to rapidly iterate, and that means quick access to experiment results data. So if you need to in the early days, build something simple and scrappy at first, and over time evolve it to support the team's needs."

Prioritize rapid iteration over perfect infrastructure by starting with simple internal tools to prove the value of testing.

Templates & Frameworks

  • EVELYN (Experiment Velocity Engine Lifting Your Numbers) - Airtable Template (Introducing DRICE: a modern prioritization framework) - A batteries-included Airtable template for managing growth experiment prioritization using RICE/DRICE
  • Noom's Experimentation Velocity Principles (How to win in consumer subscription) - A set of operating principles for running a high-velocity experimentation program in growth
  • 4-Step Conversion Optimization Process (Prioritizing conversion opportunities) - A structured end-to-end process for identifying, prioritizing, executing, and learning from conversion optimization work
  • Experiment Design Template (Breaking into growth) - A Google Doc template for designing and running growth experiments
  • Impact and Learnings Review Meeting (Ben Williams) - A weekly document and meeting structure used by growth teams to discuss and socialize experiment learnings.
  • 6 Guidelines for Experiment Urgency (The secret to Duolingo’s exponential growth) - Tactical guidelines for moving quickly on experiments to maximize compound growth, used at Duolingo
  • Growth Ideas Brainstorming Framework ('How Might We…?') (Growth ideas) - A facilitation approach for running team brainstorming sessions where you go through a categorized list of growth ideas and apply 'How might we…?' framing to ge
  • Conversion Optimization Decision Tree: Experiment vs. Ship (Strategy and tactics for increasing conversion) - Guidance on when to A/B test conversion changes vs. when to just ship them

See references/artifacts.md for the full list with details.

Questions to Help Users

  • "What is the single North Star metric you are currently trying to move?"
  • "How many experiments are you currently running per week?"
  • "What is the estimated engineering cost versus the predicted impact for your top three ideas?"
  • "Do you have a standardized process for sharing experiment learnings across the whole team?"
  • "Is your team autonomous enough to launch experiments without multi-level approvals?"
  • "What percentage of your user base actually encounters the flow you are planning to optimize?"

Common Mistakes to Flag

  • Waiting for silver bullets - Teams often stall growth by looking for one massive feature instead of accumulating many small optimizations.
  • Paralysis by testing - Applying rigorous A/B testing to every minor change can slow down execution if there is not enough data volume.
  • Ignoring the addressable pie - Failing to factor in how many users actually see a change leads to overestimating the real-world impact.
  • High-friction approvals - Requiring multiple levels of sign-off for experiments kills the momentum needed for a high-velocity culture.

Deep Dive

For all 16 sourced insights from 10 guests, see references/guest-insights.md

Related Skills

  • Growth Model
  • Acquisition Channels
  • User Onboarding Activation
  • Retention Engagement

Bundled files

The model reads these on demand while the skill is loaded. They are exposed as readable files and are never executed.

Frequently asked questions

What does the Growth Experimentation AI skill do?

Help users build and scale a high-velocity growth experimentation engine that prioritizes impact and fosters a culture of rapid learning.

Why use Growth Experimentation on TypingMind?

Because you install it once and use it with any model. Growth Experimentation is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Growth Experimentation in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/RefoundAI/lenny-skills/tree/main/skills/growth-experimentation. TypingMind reads its SKILL.md and bundles its files and installs it as a skill you can enable per chat.

Which AI models can use Growth Experimentation?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Growth Experimentation?

As many as you like. As long as a model supports skills, you can use Growth Experimentation with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Growth Experimentation AI skill free?

Yes. It is published on GitHub by RefoundAI under the MIT license. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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