· Professor Emeritus and Adjunct Professor, University of Waterloo, Cheriton School of Computer Science2024–
· Adjunct Research Professor, Carleton University, School of Mathematics and Statistics2022–
· Professor, University of Waterloo, David R. Cheriton School of Computer Science1998–
· Faculty Member (various positions), University of Waterloo, Department of Combinatorics and Optimization1998–
· Assistant Professor, Associate Professor, Full Professor, University of Manitoba, Department of Computer Science1982–