John has worked for a number of different employers in his career: .
| Period | Employer |
|---|---|
| 1998 - 2011 | Booz & Company (Stationed in London, Sydney, Washington and Amsterdam) |
| 1992 - 1998 | Mass Transit Railway Corporation, Hong Kong |
| 1988 - 1992 | Alstom Railway Projects Division, Australia |
| 1980 - 1988 | New South Wales State Rail Authority, Sydney Australia (now called RailCorp) |