Lektor (Associate Professor), Institut for Matematik og Datalogi, University of Southern Denmark, 1992-present.
Visiting Associate Researcher, Department of Computer Science, University of California - Irvine, fall semester 2007.
Visiting Faculty Member, Department of Computer Science, University of Toronto, fall semester 2002.
Visiting Associate Professor, Computer Sciences Department, University of Wisconsin - Madison, spring semester 1997.
Lektorvikar (Visiting Associate Professor), Institut for Matematik og Datalogi, Odense University, 1991-1992.
Associate Professor, Department of Mathematical Sciences, Loyola University Chicago, 1990-1991.
Lektorvikar (Visiting Associate Professor), Datalogisk Afdeling, Aarhus University, 1989-90.
Assistant Professor, Department of Computer Science, University of Chicago, 1983-89.
Research Assistant, University of California, Berkeley, summer 1981 and 1982-83.
Teaching Associate, Computer Science Division, University of California, Berkeley, winter quarter 1982.
Programmer/Analyst, Laboratory for Astrophysics and Space Research, University of Chicago, February 1978 - August 1979.
Teaching Assistant, Computer Science Department, University of Wisconsin, Madison, Fall semester 1977.
Research Associate, Undergraduate Research Participant, and Student Aide; Applied Mathematics Division, Center for Educational Affairs, and Applied Physics Division; Argonne National Laboratory, Argonne, Illinois, summers of 1975, 1976, 1977, and half-time 1976-77.