Beaver

The relentless builder who turns ideas into global infrastructure.

Luis von Ahn is the quintessential beaver — a tireless, methodical creator who doesn't stop until the job is done right. He invented CAPTCHA and reCAPTCHA, then channeled that into Duolingo, obsessively engineering it into one of the world's most-used educational platforms. His approach is craft-driven and detail-obsessed: he famously agonizes over product decisions, runs endless experiments, and has built systems used by hundreds of millions — all driven by an almost compulsive need to build things that work perfectly at scale.