Sameera Horawalavithana is a Ph.D. candidate in the Department of Computer Science and Engineering, University of South Florida. His research spans two big projects related to computational social science, privacy and machine learning: an investigation in the inherent privacy of network datasets (supported by the National Science Foundation); and developing a micro-level social simulator for online media using machine-learning algorithms (sponsored by DARPA). In the SocialSim project, he developed a social simulator (MCAS) that is able to accurately forecast individual user engagements on Twitter across multiple social contexts (e.g., Venezuelan political crisis, Chinese and Russian influence campaigns, security vulnerabilities, etc.). His most recent accomplishments include the best performing solution at DARPA SocialSim Challenge (January, 2020), and the winner of the Grand Challenge at North American Social Networks (NASN) Conference (January, 2021).