Every product leader wrestles with the same tradeoff: move fast and risk breaking things, or move slow and risk irrelevance. But what if the real accelerator wasn’t cutting corners—it was systematizing experimentation? In this episode, Hannah Clark sits down with Jean Castanon, VP of Digital Product at American Express, to explore how his team quadrupled their testing velocity in a year, redefined what “success” in experiments really means, and built a referral program that became Amex’s seco...