I read about all the case interviews I can find before the interview. You shouldn't have any problems with them if you gather all the information you can get from Glassdoor and other websites. I think I did OK in the case interviews, but what impressed the interviewers were the behavior questions I prepared. They were trying to match your experience with their real situation work. So if you read all the case interviews online, you can get a general idea of what this position does in the company. And when you do prepare for the behavior questions, you should try to make them similar to the case interviews you read. So give them what they are looking for and make them believe that you can fill the role with former experience and knowledge. Try to be confident and don't panic. Casers are very friendly and there to help you when you need it. Good luck.