Theory and applications of graph transformation; graph-based programming models; rewriting systems; theoretical computer science.
1987-1993 - Research Associate, University of Bremen, Germany.
1993-2000 - Assistant Professor, University of Bremen, Germany.
2000-2001 - Lecturer, University of York.
2001 to present - Senior Lecturer, University of York.
Visiting Researcher at Heriot-Watt University (Edinburgh).
Visiting Researcher at University of Nijmegen (The Netherlands) and Free University of Amsterdam (The Netherlands) for more than two years in total.