Michael Mark rarely gives interviews, which makes him stand out from most venture investors who are eager to build a public profile; he came out of MIT as a math major, co-founded his first tech company at 21 with a 25-year-old MIT professor, and went on to help build companies like Interleaf and Progress Software while also becoming known across Boston tech for his role in some of the most memorable pivots, including Netegrity, Pixability, EXOS, and LoopPay. Over decades he has invested in hundreds of startups, often betting on a founder even before he fully believes in their original idea, and he tends to stay closely involved as a mentor and board member rather than acting as a distant source of money, all while holding onto the view that almost no startup ends up following its original plan.