Prior to this appointment, he held a postdoctoral fellow position (March 2006 – September 2007) and later a lecturer position (Fall 2007) at the Department of Informatics and Telecommunications of the University of Athens. Prior to that, he also worked at AT&T Labs-Research as an intern (June-August 2003). He received his Ph.D. degree in Computer Science from the University of Maryland in August, 2005.