| 06/2013 | BITinklusiv | CN | CN |
| 03/2012 | SecureNet | CN | CN |
| 12/2010 | TAE | CN | CN |
| 06/2010 | linuxhotel | CN | CN |
| 03/2010 | IT-Aus- und Fortbildung | CN | CN |
| 03/2009 - 08/2009 | IT.NRW | CN | CN |
| 03/2001 - 03/2004 | FH Dortmund | CN | |
| 08/1999 - 03/2001 | FH Gelsenkirchen | CN | |
| 08/1995 - 08/1998 | Westfalen-Kolleg Dortmund | CN | CN |
| 01/1995 - 06/1995 | GWW Unna | CN | CN |
| 09/2009 - | IT.NRW | CN |
| 12/2007 - 01/2008 | Ampelmann | CN |
| 09/2005 - 12/2006 | European Space Agency | CN |
| 06/2003 - 03/2004 | Electronic Arts | CN |
| 04/2000 - 05/2001 | Zimbo | CN |
| 01/1994 - 12/1994 | Bundeswehr | CN |