In the StarTrek universe:
You would serve in starfleet as a Commander. You have a command position. You may have started your career in Starfleet by working in medical. Any of the following positions maybe available on a Starship:
Some people are not as interested in technology as the people behind it. They believe that a society should be more than just a bunch of wires and machines. Our technology may tell us where we are going, but does it really tell you what we paid to get it? The success of every mission is measured on the health of the crew. Even though technology can be repaired, there are some things which can't be replaced.
:P and here i am thinking i would get the position as a cleaner..