He obtained his PhD from Carnegie Mellon University in 2003, and worked at the IBM T.J. Watson Research Center until 2011, where he also managed the Algorithms group. His main research interests are the design and analysis of approximation and online algorithms. For his work, he has co-received best paper awards at FOCS 2011, ESA 2011 and ESA 2010, and also IBM Research best paper awards for 2007 and 2010.