Stripe: Patrick and John Collison

Brothers Patrick and John Collison founded and sold their first company before they turned 20. They created software to help eBay users manage inventory online, which set them on a path to help make e-commerce frictionless. Today, John and Patrick are the founders of Stripe, a software company that uses just a few lines of code to power the payment system of companies like Lyft, Warby Parker and Target. Plus, for our postscript "How You Built That," how Robert Armstrong turned his grandma's cookie recipe into "G Mommas," buttery, bite-sized pecan-chocolate-chip cookies that are now sold in stores across the Southeast U.S.