Poorly structured, lack of organisation, poor time management, unrealistic of day-to-day duties. I was told the wrong information entirely by the recruiter as one of the interviewers didn't have my CV and thought I was applying for a Python position! I was given a 110% guarantee of particular questions coming up so I prepared well but they were completely different and unrelated. If I was told they may have been different I would've prepared accordingly but I was given a cast-iron guarantee they were of a certain type. His response was "they must've changed them". Well that's comforting for the next candidate(!) so I feel massively deceived and ill-prepared. You couldn't make it up. It was my first interview in 7 years so naturally I was very nervous but this was the cherry on top.