Well in video games and mmorpg, are there specific teams or careers where people design characters and classes? To my knowledge, it takes a lot of work to design and balance classes and even more effort in non-class mmorpgs where devs need to make it so that players don't opt for only one set of skills.
1) What kind of people do these jobs designing and balancing classes? Is it just part of the general game designer job? Where can I read up more about this?
2) And how exactly do people come up with classes and the idea behind class design? I'd like to learn more about this aspect of game design.

thanks.