Breakthroughs in generative AI have created enormous opportunities for humans to learn from computers. We can use them to explain the news, understand historical concepts, fix our coding errors, and so forth. But of course, AI also has to learn from human. The technology digests enormous amounts of written text, and often relies on human feedback to calibrate its models. Luis von Ahn has been at the forefront of these back and forth interactions for years. He is currently the CEO and co-founder of Duolingo, the language learning app, but prior to that, he was one of the original developers of CAPTCHAs, the little puzzles you solve to log into websites and prove that you're a human. And of course, in the process of proving your humanity, you're also training computers to get better at identifying red lights, cross walks, bicycles and wavy letters. On this episode, we discuss the history of his work, the future of CAPTCHAs, the success of Duolingo and how he is using today's advanced AI models in aid of language learnings.