In this episode of The Biotech Startups Podcast, Caitlyn Krebs, co-founder and CEO of Nalu Bio, traces her path from building the Bay Area's biotech ecosystem to operating at the cutting edge of science and business. She shares how launching BayBioNEST taught her what it really takes—beyond great science—to build durable companies, before diving into her time at Entelos, where she helped pioneer virtual patients and digital twins nearly twenty years before AI became a buzzword, and unpacks what BD actually means in biotech, from navigating black-box skepticism to running "bake-off" pilots that let the data speak for itself. The conversation then shifts to Tethys Bioscience, where Caitlyn helped bring a prediabetes diagnostic to market—winning over physicians, employers, and major payers like Aetna, United, and Cigna—only to watch a single Medicare/CMS misstep shutter a well-funded company, and what every founder can learn from that hard-won experience.