Nice idea but it feels empty after reaching prestige. Probably because prestige does not extend the core gameplay. And the fixed 5 seconds delay between new contracts make speeding up the workers kind of a moot point.
Two suggestions:
First another layer after the first prestige. Perhaps some kind of Research or Controlling which boosts the working floor.
Second - Secondary skills which affect the progress. For example for sales a marketing skill which reduces the 5 seconds delay. Design could get a skill which boosts the worth of a contract every now and then. And so on.