Brian Shortsleeve is a growth-focused investor and business leader with a strong track record of scaling growth-stage companies. He is Managing Partner at M33 Growth, a growth equity firm he co-founded, and serves on the Board of Titan Cloud Software, where he brings expertise in go-to-market strategy, operational scale, and long-term value creation.

At M33, Brian also serves on the boards of W Energy Software, L2L, GoDocs, and PerformLine. Prior to founding M33, he was Chief Administrator and Acting General Manager of the MBTA, where he was appointed by Governor Charlie Baker to lead a major turnaround focused on financial sustainability and infrastructure modernization.

Prior to MBTA and M33, Brian held leadership roles at Bain & Company, H.I.G. Capital, and General Catalyst, where he led investments in software and technology-enabled services. Brian is a graduate of Harvard College and Harvard Business School and served as a Marine Corps officer overseas.