The Profile Dossier: Luis von Ahn, the Immigrant Founder Who Built the World’s Most Downloaded Education App

“The attitude of just finding a way to become useful gets you a lot farther.”

Luis von Ahn invented an app so addicting that it attracts nearly 50 million users per month. But here’s the catch: It’s not a social network.

Von Ahn is the entrepreneur behind the popular language-learning platform Duolingo. The app offers 40 languages — including English, Spanish, French, German, and even High Valyrian (the fictional language featured…