Brendan Foody: How Mercor hit $500M run rate in 16 months

ℹ️ EPISODE INFO

Released

September 18, 2025

Duration

1h 7m

Channel

Lenny's Podcast

Watch on YouTube

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📝 EPISODE DESCRIPTION

Brendan Foody is the CEO and co-founder of Mercor, the fastest-growing company in history to go from $1M to $500M in revenue (in just 17 months!). At 22, he is also the youngest American unicorn founder ever. Mercor works with 6 of the Magnificent 7 and all top 5 AI labs to help them hire experts to create evaluations and training data that improve their models. In this conversation, Brendan explains why evals have become the critical bottleneck for AI progress, how he discovered this massive opportunity, and what the future of work might look like in an AI-driven economy. _Big thank you to Peter Deng for introducing me to Brendan._ *What you’ll learn:*

1. Why evals are becoming the primary bottleneck for AI progress and what this means for AI startups
2. How Mercor grew to $500M revenue in 17 months (fastest in history)
3. Brendan’s meeting with xAI that changed his company’s trajectory
4. Which skills and jobs will remain most valuable as AI continues to advance (hint: jobs with “elastic” demand)
5. Why Brendan believes AGI and superintelligence are not happening anytime soon
6. The three unique core values that drove Mercor’s success
7. How Harvard Lampoon writers are making Claude funnier

*Brought to you by:* WorkOS—Modern identity platform for B2B SaaS, free up to 1 million MAUs: https://workos.com/lenny Jira Product Discovery—Atlassian’s new prioritization and roadmapping tool built for product teams: https://atlassian.com/lenny Enterpret—Transform customer feedback into product growth: https://enterpret.com/lenny *Transcript:* https://www.lennysnewsletter.com/p/experts-writing-ai-evals-brendan-foody *My biggest takeaways (for paid newsletter subscribers):* https://www.lennysnewsletter.com/i/173303790/my-biggest-takeaways-from-this-conversation *Where to find Brendan Foody:*

• X: https://x.com/BrendanFoody
• LinkedIn: https://www.linkedin.com/in/brendan-foody-2995ab10b/

*Where to find Lenny:*

• Newsletter: https://www.lennysnewsletter.com
• X: https://twitter.com/lennysan
• LinkedIn: https://www.linkedin.com/in/lennyrachitsky/

*In this episode, we cover:* (00:00) Introduction to Brendan Foody and Mercor (05:38) The “era of evals” (09:26) Understanding the AI training landscape (17:10) The future of work and AI (25:54) The evolution of labor markets (29:55) Understanding how AI models are trained (38:58) Building Mercor (53:27) Lessons from past ventures (56:55) The future of AI and model improvement (01:00:41) His personal use of AI and final thoughts *Referenced:*

• Mercor: https://mercor.com/
• No Priors Ep. 110 | With Mercor CEO and Co-Founder Brendan Foody: https://www.youtube.com/watch?v=vnkVYLhGd_s
• Sarah Guo’s post on X about evals: https://x.com/saranormous/status/1948565353514316021
• Cursor: https://cursor.com/
• The rise of Cursor: The $300M ARR AI tool that engineers can’t stop using | Michael Truell (co-founder and CEO): https://www.lennysnewsletter.com/p/the-rise-of-cursor-michael-truell
• Lovable: https://lovable.dev/
• Building Lovable: $10M ARR in 60 days with 15 people | Anton Osika (CEO and co-founder): https://www.lennysnewsletter.com/p/building-lovable-anton-osika
• Bolt: https://bolt.new/
• Inside Bolt: From near-death to ~$40m ARR in 5 months—one of the fastest-growing products in history | Eric Simons (founder and CEO of StackBlitz): https://www.lennysnewsletter.com/p/inside-bolt-eric-simons
• Replit: https://replit.com/
• Behind the product: Replit | Amjad Masad (co-founder and CEO): https://www.lennysnewsletter.com/p/behind-the-product-replit-amjad-masad
• v0: https://v0.app/

•Everyone’s an engineer now: Inside v0’s mission to create a hundred million builders | Guillermo Rauch (founder and CEO of Vercel, creators of v0 and Next.js): https://www.lennysnewsletter.com/p/everyones-an-engineer-now-guillermo-rauch

• Handshake: https://joinhandshake.com/
• Inside the expert network training every frontier AI model | Garrett Lord (Handshake CEO): https://www.lennysnewsletter.com/p/inside-handshake-garrett-lord
• Scale: https://scale.com/
• Surge: https://www.surgehq.ai/
• Andrej Karpathy on X: https://x.com/karpathy
• Anthropic co-founder on quitting OpenAI, AGI predictions, $100M talent wars, 20% unemployment, and the nightmare scenarios keeping him up at night | Ben Mann: https://www.lennysnewsletter.com/p/anthropic-co-founder-benjamin-mann
• Amber Yang’s post on X about creating RL training data: https://x.com/theamberyang/status/1952462320174600385
• Codex: https://openai.com/codex/
• Claude code: https://www.anthropic.com/claude-code
• Neuralink: https://neuralink.com/
• Alphasights: https://www.alphasights.com/
• GLG: https://glginsights.com/

...References continued at: https://www.lennysnewsletter.com/p/experts-writing-ai-evals-brendan-foody _Production and marketing by https://penname.co/._ _For inquiries about sponsoring the podcast, email podcast@lennyrachitsky.com._ Lenny may be an investor in the companies discussed.

🎤 SPEAKERS

• Brendan Foody

  guest

• Lenny Rachitsky

  host

🧾 EPISODE SUMMARY

In this episode of Lenny's Podcast, featuring Brendan Foody and Lenny Rachitsky, Brendan Foody: How Mercor hit $500M run rate in 16 months explores experts Writing AI Evals Are Powering History’s Fastest-Growing Companies Lenny Rachitsky interviews Brendan Foody, CEO and co-founder of Merkor, a labor marketplace that supplies expert talent to AI labs to write evals and post-training data, enabling rapid improvements in model capabilities.

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