Marina Hatsopoulos, entrepreneur and lecturer for MIT's 15.393 Nuts and Bolts of New Ventures, walks through the errors founders repeat across ventures, the kind that experienced investors, partners, and employees learn to watch for. Drawing on the course's IAP 2025 session, she covers recurring missteps in hiring, fundraising, equity splits, and team dynamics that sink otherwise promising startups. The session is framed as a checklist against pitfalls rather than a success story, matching the practical, case based tone of the course, which pairs Hatsopoulos's own experience founding and running Z Corporation with guest input from working investors. At 83 minutes, this is a full class session with discussion, not a highlight reel, aimed at students actually building companies rather than casual viewers looking for startup inspiration. It closes out a broader unit on the operational realities of early stage ventures.