Michael Seibel is a former two-time founder who built Justin.tv/Twitch and Socialcam before becoming a Y Combinator partner, giving him firsthand experience with both hypergrowth and acquisitions that he draws on when advising founders. He's known for turning thousands of founder interactions into a structured playbook that emphasizes simple products and rapid iteration, while also being a consistent advocate for founders from nontraditional backgrounds who may not have Silicon Valley networks. Michael Seibel is a former two-time founder who built Justin.tv/Twitch and Socialcam before becoming a Y Combinator partner, giving him firsthand experience with both hypergrowth and acquisitions that he draws on when advising founders. He's known for turning thousands of founder interactions into a structured playbook that emphasizes simple products and rapid iteration, while also being a consistent advocate for founders from nontraditional backgrounds who may not have Silicon Valley networks.