Pros
- working on amazing things which push forward humans' understanding of the universe,
- incredible freedom at work, effects are what matters, you can organize everything as you like and experience atmosphere of scientific organisation unlike anywhere else,
- great learning opportunities, a lot of seminars are organized on many subjects, not only physics, practically every day you can take part in great lectures and constantly develop not only work skills but also general knowledge,
- above all, great people you work with, who will help you thrive, who will help you learn, help you develop, who will care more about YOU than work you do, more friends than colleagues
- opportunities to take part in conferences, often in great locations abroad, you can also enroll in French courses in CERN or other technical/software courses, they really invest a lot in any person working there
- even as student you are considered real part of CERN community, no different than person working there for 20 years, that's remarkable
- best place I ever worked and probably also best I ever will
Cons
- you need to be an organized person, able to set your own goals, although that may seem like good thing it is also sometimes very demanding and certainly not for everyone