Getting Past First Round

Going to assume this is for SA IB. From my experience, there are three components of first rounds.

1) Technicals. Depending on the bank these will range from your run of the mill dcf/accounting to lbo/merger models. Technicals are pretty much table stakes and if you are messing up any technicals it is unlikely you will get the second interview. The solution to this is study until you have everything down. For BB/MM having the 400 question guide down should be enough. For boutiques, have a good knowledge of lbos and m&a models.

2) Behaviorals. These are your basic strengths/weaknesses etc. These are much harder and more important than many realize. Many interviewees assume that they will be good at these and don't practice them. This is a mistake. You should have a compelling story for every possible behavioral you could be asked. Again, there are guides that will give you the most common questions. It also helps to have a bank of 15 or so stories from all your past internship/extracurricular/academic experiences that you can draw from and modify to behavioral questions you haven't come across before.

3) Fit. I separate this from behaviorals as this isn't always something that is tested by specific questions. Are you personable? Can you have some small talk with the interviewer as the interview starts? Can you show humility when necessary? Do you have intelligent questions to ask after the interview is over? The answer should be yes to all of these.

Maybe you need to review your process of evaluating your interviews as something is definitely not working. Five interviews is more than many applicants will get at all. Sit down and be completely honest with yourself about your interviews. Go through each one and try to identify areas you could work on. Email your interviewers afterwards asking if you can improve on anything when you don't get the next round. Even when someone interviews well, there are always areas to improve, so if you think you are perfect, then you are deluding yourself. I can't diagnose this problem for you as I am not in the room with you as you interview. The guidelines above will hopefully help on a a basic level, but the true answer to this question can only come from introspection.