Marshall has extensive experience in business management and consulting and has worked for Sovereign Infrastructure Group for the last four years. Additionally, he has worked to advise companies such as BP Oil, Unplugged Capitol, and Blue Northern Energy on investment and infrastructure development. Earlier in his career he also did work for Northwestern University and Becerra Educational Consulting, Inc. on software development to advance student leadership skills and educational tutoring.

With his wife and new UB Professor of Music, Melissa White, Marshall has participated in discussions hosted by the University of Michigan about career development and entrepreneurship in the arts and he currently serves as an associate board member of the Chicago Sinfonietta, which has been described by the Chicago Tribune as "the city's hippest orchestra" and was a winner of a 2016 MacArthur Award for Creative and Effective Institutions.