· Trustee, California Institute of Technology2025–
· SVP, Research and Systems Infrastructure, Google2011–
· Partner and Founders' Coach, Sequoia Capital2011–
· Senior VP, Engineering, Google2007–2011
· Senior Engineering Director, Google2004–
· COO, VP of Engineering, Director & Founder, Entrisphere2002–
· CEO, VP of Engineering, Board Director & Founder, Entrisphere2000–2002
· Bell Labs Research Silicon Valley Senior Vice President, Bell Labs, Lucent Technologies1998–2000
· Consulting Professor of Computer Science, Stanford University1998–2001
· Internet Software Vice President and Chief Technical Officer, Communications Software Group, Lucent Technologies1997–1998
· Computing Sciences Research Center Vice President, Bell Labs, Lucent Technologies1996–1999
· Head, Scientific Computing Research Department, AT&T Bell Laboratories1993–1994
· Adjunct Professor of Computer Science, Duke University1991–1999
· Industrial Lectureship, Department of Computer Science, Stanford University1991–
· Adjunct Associate Professor of Computer Science, Duke University1984–1991
· Member of Technical Staff, Computing Mathematics Research Department, AT&T Bell Laboratories1980–1993
· M.S., Computer Science, Stanford University1977–
· B.S. (with honors), Mathematics, California Institute of Technology1975–
· M.S., Mathematics, California Institute of Technology1975–
· PhD in Computer Science, Stanford University1975–1980
· Research and Teaching Assistant, Department of Computer Science, Stanford University1975–1980
· Programmer/Analyst, Office of Personnel Services, California State University1973–1974
· Application and Systems Programmer, Computer Center, California State University1969–1972