Once you join a company and start working full-time, aggressively volunteer to take on tasks that aren't your specialty. In any company there's always something

Once you join a company and start working full-time, aggressively volunteer to take on tasks that aren't your specialty. In any company there's always something that needs to be done but no one has the time to do - setting up release automation or test harnesses, build jobs etc. You not only learn more technical skills, you also get an idea of what other types of work you might enjoy doing.