I am a Research Engineering Director managing a team of about 50 researchers within Google AI.

From October 2001 to March 2014, I was a researcher at the (now defunct) Microsoft Research Silicon Valley lab. In that role, I worked on various aspects of social search; link-based ranking algorithms for web search results; the Scalable Hyperlink Store, a distributed in-memory store for web graphs; heuristics for detecting spam web pages; PageTurner, a large-scale study of the evolution of web pages; and Boxwood, a distributed B-Tree system.

From October 1993 to September 2001, I worked at Digital Equipment's (later Compaq's) Systems Research Center. Projects at SRC included Mercator, a high-performance distributed web crawler; JCAT, a web-based algorithm animation system; and Obliq-3D, a scripting system for 3D animations.

I am an ACM Fellow and an IEEE Fellow. I am currently serving on the ACM Publications Board, as program co-chair of WWW 2021, and as co-chair of DESIRES 2021. In the past, I served as an associate editor of the ACM Transactions on the Web from 2005 until 2011 and as editor-in-chief from 2011 until 2015, as co-chair of the news section of the Communications of the ACM from 2008 until 2014, conference chair of WSDM 2008, and program co-chair of WWW 2004.