Mandel was an IBM employee from 1982 – 1993. As a member of IBM’s prestigious Common User Access (CUA) user interface architecture group, Mandel conducted research on Graphical User Interfaces (GUIs) and Object-Oriented User Interfaces (OOUIs), prototyped the IBM OS/2 operating systems interface, and wrote the landmark book, Object-Oriented Interface Design: IBM Common User Access Guidelines.
Mandel also has consulted with IBM on numerous user experience projects in the past 10 years.