Pros
Fidessa is has an overall fun atmosphere and is filled to the brim with really smart motivated people. The executive (C level) suite is very accessible and is generally open to listen to any ideas or thoughts. There's a horrendously skewed male to female ratio but that's to be expected in a technology firm. (That could be interpreted as pro or con)
Cons
Zero upward mobility. Middle management bullshits quite a bit in their attempt to retain staff. The truth is, they have no power and cannot get passed the red tape that is constantly laid out by the middle aged British boys club. Departments compete and ate abrasives to each other instead of working together to promote innovative solutions. I reckon it's kept this way so management can keep legacy procedures and technology in place. They do not merit hard work or extra effort. This place is not for the ambitious. If you want to check out and coast then apply!