· Researcher at the Center for the Mathematics of Information (CMI), California Institute of Technology (Caltech)2024–
· Professor of Mathematics, Scuola Normale1986–1996
· Professor of Electrical Engineering, MIT1973–2023
· Associate Professor, MIT1970–1973
· Visiting Associate Professor, MIT1969–1970
· Associate Professor, Case Western Reserve University1967–1969
· Assistant Professor, Case Western Reserve University1965–1967
· Fellow, Central Electricity Generating Board1962–1965
· Software Engineer, Battelle Memorial Institute1961–1962
· Development Engineer, Brown, Boveri & Cie1957–1961