Geoff has been an investor in, board member of, and advisor to a variety of start-up companies, mostly in the San Francisco Bay Area. He is also a partner at Y Combinator. From 2007-2009 Geoff was the Chief Executive Officer of Lala Media, Inc., an innovative cloud music start-up in Palo Alto that was purchased by Apple in December of 2009. Geoff worked at Yahoo! from 1997-2006 after their 1997 acquisition of Four11 Corp. At Four11 Geoff was the VP of Engineering and led the creation of Yahoo! Mail's predecessor, RocketMail. At Yahoo! Geoff was Senior Vice President and general manager of the Communications Business Unit and subsequently served as the company's Chief Product Officer. Geoff holds a B.A. in Computer Science from Dartmouth College, an M.S. in Computer Science from Stanford University, and an M.B.A. from INSEAD, the European Institute of Business Administration.