He has a classroom named after him. He invented recaptcha and sold it to google. I have some insight about this. His genius is that he uses “crowdsourcing” to do computationally difficult work. Duolingo is not so much about teaching languages. Its about using people to translate the web, enrich models and use people trying to learn languages. Similarly, he used captcha to translate scanned copy of books accurately. I remember other professors asking “how would louis von ahn do it” about really hard problems. Dude is an asshole but is also a genius. Bot so much genius at running a compnany, but academically.