Each company just like real life can hire employees from Dev City each unique in their own way, with more employees work can go faster. Additionally employees can be sent on training courses to make them more efficient. Of course not everyone works out so you can fire them too!
The amount of employees you can hire varies on what types of property you have. Each property type has it's own attributes, for example 1 building type might allow for 5 employees but little storage space while another allows 0 employees but much more storage space. On top of property development you can customise your area by adding tree's, flowers, security check-points and even change your ground colour!
There is much much more too Dev City RPG so why not go check it out. It's free to play, register or if a Facebook member you can log-in without registration and instantly play!