Bob has held a number of security and software engineering management positions over the past 20 years at companies such as Andersen Consulting, Netscape, AOL, Sun (iPlanet/AOL alliance), and Red Hat. He ran corporate security at Netscape before leading the cryptography teams there and subsequent companies. He was the Engineering Director responsible for the Certificate System, a PKI server used in numerous sensitive environments. He is currently the Director of Information Security at Twitter.