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Lennybot: A curated second brain for product leaders

Lennybot is a worked example of expert-clone AI. Hundreds of named practitioners curated into a queryable second brain, with citations, voice mode, and a freemium entry point. Worth knowing as a tool and as a product pattern.

AI ToolsLennybotProduct ManagementRAGExpert ClonesDelphi

In this section I review one AI-powered application and demonstrate how it can be used to create new value.

Building products is a multi-faceted challenge and profession. I had the opportunity to be Director of Products in two startups, to help a variety of enterprise customers re-imagine products in my role as Digital Innovation Lead at AWS, and am now helping leaders and teams rethink products with AI. One of the most helpful and inspiring sources for me is Lenny's podcast (I sometimes share relevant episodes here).

Lennybot is a marvelous extension of that podcast, and is also a great example of a well-crafted AI product. That's why I wanted to include it as a recommended tool here. Lennybot shows us how the content of hundreds of podcast guests is the product. You're not talking to just Lenny, and you're not querying a general-purpose LLM. You're getting advice and insights from a curated corpus of product and growth expertise drawn from 200+ named practitioners, people like Melanie Perkins from Canva and Howie Liu from Airtable, plus hundreds more.

What I like about it

Corpus over capability. The win is that 500 newsletter issues plus 200 podcast interviews with named product leaders are almost certainly the best-curated PM and growth knowledge base anyone has assembled. When I ask a career or strategy question, the signal-to-noise ratio is dramatically higher than a general model.

Citations. Every substantive claim points back to a source — a guest, an episode, a post. That reduces hallucination risk and, more importantly, lets me verify. If a cited framework matters to a decision I'm actually making, I can go read the original.

Voice and call. The web chat works well for research. The call mode, where it responds in Lenny's cloned voice, makes it usable while walking or driving, which many chatbots miss. It's built on Delphi, a platform that turns expert content into interactive clones with citations. Delphi is worth knowing about as a broader pattern in itself.

Freemium. Free to try, no friction. You can test whether this kind of tool belongs in your workflow before deciding it does.

Limitations to understand

One worldview. It's Lenny plus his guests. That's a narrow-and-deep corpus, strongest on consumer SaaS and PM career ground. If your question sits outside that territory — enterprise B2B rollouts, regulated industries — you'll get thinner answers than a general-purpose model would give you.

It's also not a builder or a build advisor. Unlike tools that produce code or designs, Lennybot advises. Don't confuse the categories. Use it to sharpen your thinking before you build, not instead of building.

And the corpus lags. It syncs periodically, so for news-driven questions ("what happened with OpenAI last week"), use a different tool.

The pattern beneath the tool

Lennybot is the most polished example I've seen of a broader pattern: rented second brains. As I cover in this issue's terminology section on Second Brain, Tiago Forte's 2026 reframe is that the bottleneck has moved from capture to context. Lennybot is literally Lenny Rachitsky's second brain made queryable by anyone. Expect more of these. Curated expert brains available on demand. They're complements to your own context store, not substitutes. A rented second brain knows its owner's domain. Only your own knows you.

For business leaders this matters in two ways. First, the tool is genuinely useful as a sounding board for product and growth questions. Second, the pattern itself — corpus, citations, voice, freemium entry — is one to study if you're thinking about how AI could amplify your own expertise inside or outside your company.

Your action step

Pick the single hardest product or career question you're carrying this week, the one you'd normally take to a peer or a mentor. Ask Lennybot before your next team conversation. Notice two things. Does the cited answer sharpen or soften your position? And does seeing the named experts behind each framework change how confidently you bring the point into the room?

Try it at lennybot.com. And if you've used another expert clone you've found genuinely useful, I'd love to hear which one.

Frequently Asked Questions

What is Lennybot?
Lennybot is an AI assistant built on Lenny Rachitsky's curated corpus — 500+ newsletter issues plus 200+ podcast interviews with named product and growth leaders. It runs on Delphi, a platform that turns expert content into interactive clones with citations. Free to try, with a paid tier for deeper use.
How is Lennybot different from a general-purpose LLM?
Three things make it different. The corpus is narrow and deep, curated from named practitioners rather than the open web. Every substantive answer cites its source, so you can verify before acting. And a voice mode in Lenny's cloned voice makes it usable while walking or driving. The trade-off is coverage — for B2B enterprise rollouts or news-driven questions, a general model is still better.
Who should use Lennybot?
Product managers, growth leaders, and consumer-SaaS founders who want a sharper sounding board on career and strategy questions. Use it before a team conversation to test whether named experts agree with your position. Don't use it as a builder — it advises, it doesn't ship.

Originally published in Think Big Newsletter #28 on Amir Elion's Think Big Newsletter.

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