What does a Bar Back do?

A bar back does many different things. Some of the duties range from washing gles to hauling kegs. It just depends on the bar. I tend bar at the beach, and it is very busy in the summer, so I tip my bar back quite well. Without a good bar back the bartender is not going to make money. Yes, it is a "back busting" job as you put it. If the bar is not busy, though, you might just stand around and make no money.