Incredibly arrogant administration: in 20 years of working at different companies, I have never experienced comparable disregard
Students and other non-permanent personell have zero lobby (staff association only cares about pensions)
Many selfish managers that are not working at CERN out of passion for science goals but to protect their personal little kingdom and play power games
Conflicts of interest due to couples working together
Many permanent researchers behave and act like civil servants, not scientists
High probability of getting locked in or hunting the golden cage
Work contracts and employment rules do not have to follow any EU or Swiss standards. CERN basically does what they please.
