Socialism

I see many self-identified socialists imply that, in a socialist society, people would constantly be doing different jobs and would split their labour between many different jobs rather than specialize. It definitely makes sense when it comes to jobs that don't require too much specialization, but how does this work with highly specific jobs that require a disproportionately high amount of resources to become skilled in? Would they spend more time on a specialization, would they frequently rotate the same as everyone else?