Pretty standard competency-based questions. Like which achievement are you most proud of, last time you solved a conflict at work, what are your weaknesses/strengths, who do you look up to, ..then a more 'consulting' question like...how many tires are sold in the UK in a year. You have to think out loud, they always wanted specific numbers.
I wouldn't say the interview was hard..questions were pretty common like you would expect from any other interview. I was just very nervous because of the rather unfriendly attitude of the interviewers. One even left out a sigh and shook his head while the other guy was interviewing me, and he started writing down his comments on my performance on a paper. I thought it was incredibly unprofessional and it made me feel even worse than I already felt.