Sifakis is assistant professor of Computer Science at UW–Madison. Alongside other UW computer scientists and UW medical researchers, Sifakis is working to invent a virtual surgery simulator. He has worked as a consultant with Intel Corporation, SimQuest LLC, and Walt Disney Animation Studios. He focuses his research on computer graphics, physics-based modeling/simulation, and scientific computing and is interested in algorithms that can simulate parts of the human body for biomechanics and virtual surgery. He earned his PhD in Computer Science from Stanford University and conducted postdoctoral research at the University of California–Los Angeles.