Marzullo is on the advisory board for the National Science Foundation Office of International Science and Engineering and is the head of the North American section of the international iSchools organization. He is also an ACM Fellow, who comprise an elite group that represents less than 1% of the ACM's global membership and who are recognized for significant contributions to the field of computation and computer science. In recent years, Marzullo's research has focused on technology in the service of people, with a growing interest in cybersecurity, privacy, and socio-technical systems, such as technology that assists in emotion regulation.

Marzullo joined the iSchool from the White House Office of Science and Technology Policy, where he served as director of the Networking and Information Technology Research and Development program. In this role, he coordinated R&D and strategic planning activities across 20+ Federal agencies in several areas, including AI, data analytics, cybersecurity, and privacy. Prior to this, Marzullo spent five years at the National Science Foundation, where he directed the Division of Computer and Network Systems in the Computer and Information Science and Engineering Directorate.