The worst candidates know the exact way to act in the interview process. Once they're in, it's really difficult to get them out. I've seen some pretty terrible

The worst candidates know the exact way to act in the interview process. Once they're in, it's really difficult to get them out. I've seen some pretty terrible behaviour, all performed absolutely fine in interviews. So much so that I believe that interviews are only useful to establish basic suitability and that most companies should hire loosely with a long probationary period. Employees that don't perform would be let go.