Murderbot is a Security Unit, an artificial person specialized to be very good at fighting. It has hacked its governor module, so it doesn't actually have to obey commands anymore, except that doesn't want anyone to realize that it has hacked its governor module, because humans are afraid of Security Units, especially of the possibility that one could be hacked.

As the books go on you realize that actually the powerful, dangerous, amoral, immortal thing that will kill you if that's cheaper than going around you is not the autonomous SecUnit, but the corporation.

I think you would like them!