Prior to working as principal deputy director of national intelligence, she served as the associate deputy director of the Central Intelligence Agency. She also held several management positions in the agency’s Directorate of Science and Technology, working to develop and deploy innovative technology in support of intelligence collection and analysis.

O’Sullivan currently serves on the boards of directors of The Aerospace Corporation, Battelle Memorial Institute, HRL Laboratories (formerly Hughes Research Laboratories) and the CIA Officers Memorial Foundation. She has served on advisory boards at Google, Adobe and Oak Ridge National Laboratory, and continues to serve on advisory boards at Noblis, Peraton and Booz Allen Hamilton. She has been an adjunct faculty member at Georgetown University’s Center for Security and Emerging Technology and continues to support study activities for the Department of Defense and the CIA.

O’Sullivan received a bachelor of science in civil engineering from Missouri Science and Technology University. She was also elected in in 2019 as a member of the National Academy of Engineering.