John Mathieson initially worked for Sinclair Research before going on to found Flare with fellow ex-Sinclair colleagues Martin Brennan and Ben Cheese.

After working at Flare on the Flare 1 and its development into the Konix Multisystem he went on to work for Atari developing the Atari Jaguar with Martin Brennan. John moved to California and worked on Jaguar 2 which never saw the light of day.

He led the development of the ill-fated NUON media processor at VM Labs. He now works for nVIDIA.