Hancock spent 29 years at IBM, where she rose to senior vice president in charge of network hardware and software.
In September 1995, she was hired away from IBM by Gil Amelio to become National Semiconductor's Executive Vice President and Chief Operating Officer (COO).
[2] At Apple, Hancock took over the Chief Technology Officer role in the midst of the floundering next-generation operating system (OS) project named Copland.
[3] To replace it, Hancock had favored Sun Microsystems's Solaris operating system over NeXT Inc.'s NeXTSTEP, and was against the eventual purchase of NeXT.
[6] Hancock was a member on the boards of several companies and academic and nonprofit institutions, including Aetna, Colgate-Palmolive, Electronic Data Systems, Ripcord Networks, Marist College, Santa Clara University, and the Pacific Council on International Policy.