Before joining the department he was a postdoctoral fellow at the Yahoo! Research labs in Santa Clara, CA. He graduated in 2000 in computer engineering and informatics from the University of Patras, Greece and in 2006 he obtained a Ph.D. in computer science from Brown University in the area of analysis of stochastic processes in computer science, under the supervision of Eli Upfal. His research interests lie in the broad areas of algorithms and probabilistic analysis, with emphasis on data-mining, web-mining, and social-network applications.