# reCAPTCHA and Duolingo: Luis von Ahn

- Show: [How I Built This](https://hardwarepodcasts.com/podcast/how-i-built-this)
- Published: 2020-05-25
- Length: 1h 04m
- Page: https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn

## Summary

Luis von Ahn, co-founder of Duolingo and reCAPTCHA, recounts how a 2000 lecture at Carnegie Mellon inspired him to create CAPTCHA to stop Yahoo spam bots, which he gave away for free. He later evolved this into reCAPTCHA to digitize books for the New York Times, selling the company to Google, before pivoting to Duolingo with co-founder Severin Hacker to provide free language education. Von Ahn details the struggle to find a sustainable business model, the decision to introduce ads and subscriptions, and the massive growth driven by the pandemic.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=0) Introduction: Luis von Ahn and the Origins of CAPTCHA
- [3:31](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=211) Childhood in Guatemala and Academic Path to Carnegie Mellon
- [8:50](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=530) Inventing CAPTCHA to Solve Yahoo's Spam Problem
- [15:16](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=916) The ESP Game and Early Crowdsourcing Research
- [20:43](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=1243) Creating reCAPTCHA to Digitize the New York Times
- [30:02](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=1802) Selling reCAPTCHA to Google and Leaving Academia
- [35:38](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=2138) Founding Duolingo with Severin Hacker
- [45:31](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=2731) Pivoting from Translation Contracts to a Free App
- [51:35](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=3095) Finding a Business Model: Ads and Subscriptions
- [56:27](https://hardwarepodcasts.com/podcast/how-i-built-this/2020-05-25-recaptcha-and-duolingo-luis-von-ahn#t=3387) Duolingo's Growth, Gamification, and Future Plans

## Topics

- [Starting a product company](https://hardwarepodcasts.com/topic/starting-a-company)
- [Pricing, margins & unit economics](https://hardwarepodcasts.com/topic/pricing-and-unit-economics)
- [Validation & product-market fit](https://hardwarepodcasts.com/topic/validation-and-product-market-fit)
- [Fundraising & investors](https://hardwarepodcasts.com/topic/fundraising)
- [AI & machine learning](https://hardwarepodcasts.com/topic/ai-and-machine-learning)

## Most relevant to

founders before launch, early-stage companies, companies scaling up

## Mentioned

- Duolingo (product)
- reCAPTCHA (product)
- Yahoo (company)
- Google (company)
- New York Times (company)
- Carnegie Mellon University (company)
- Union Square Ventures (company)
- Ashton Kutcher (other)
- Tim Ferriss (other)
- Rosetta Stone (product)
- CNN (company)
- BuzzFeed (company)
- Facebook (company)
- ESP Game (product)
- Duolingo ABC (product)

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