September 1974 - February 1978: University of Munich (wissenschaftliche Hilfskraft)
March 1978 – December 1980: Siemens AG Munich (Cobol Compiler maintenance)
January 1981 - September 1985: Logics GmbH Munich (software development)
October 1986- January 1989: freelance work (software development)
January 1989 – January 1996: Softlab GmbH (software development and project management)
February 1996 – June 2012: Microsoft Deutschland GmbH (infrastructure consulting, cloud computing)
July 2012 – March 2022: retired and guest scientist at the University of Munich
April 2022 – present: retired and independent scientist