 He joined Princeton University in 1995 and did his Ph.D under the guidance of Professor Peter Sarnak.After his Ph.D. he received the first five-year fellowship from the American Institute of Mathematics, and held positions at Princeton University, the Institute for Advanced Study, and the University of Michigan.He moved to Stanford University in 2006 where he is currently a Professor of Mathematics and the Director of the Mathematics Research Center (MRC) at Stanford.