reCAPTCHA and Duolingo: Luis von Ahn

May 25, 2020

How I built this

In 2000 Luis von Ahn was starting his PhD in computer science when he attended a talk and happened to learn about one of Yahoo's biggest problems: automated bots were signing up for millions of free Yahoo email accounts and generating tons of spam. Luis' idea to solve this problem became CAPTCHA ...See more

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