Matthew Groll is Co-Founder and CTO at Mass Magnetics (YC S26), a Boston-based deep tech startup producing domestic rare-earth permanent magnets for robotics and defense using vertically-integrated, AI-enabled supply chains.

Matthew holds a Mechanical Engineering Master's degree from MIT and previously served as a Member of Technical Staff at Draper Labs, where he built ultra-precise aerospace guidance systems and contributed to hardware for NASA and MIT.

Matthew recognized that fewer than 2% of rare-earth magnets in post-consumer hardware are ever recovered, and set out to solve America's critical materials dependency without the capital intensity or permitting burden of mining.

At Mass Magnetics, Matthew leads the technical development of AI-powered vision systems that identify and sort critical metals from post-consumer streams for reprocessing into DFARS-compliant permanent magnets, achieving end-to-end magnet production at 1/100th the capital intensity of a mine.

Mass Magnetics, backed by Y Combinator (S26) and operating out of Greentown Labs in Greater Boston and Columbus, IN, supplies the backbone materials for electric motors, sensors, and electronics that defense and aerospace manufacturers urgently need from domestic sources.