3 Part Process
1) Business Insider 1 and 2 Exams --> Straight forward, was easy in my opinion. Basic evaluation of given information, come to a conclusion and support it. Simple Ratios. Know basic calculations and support the answers with the material given.
2) HireVue --> 30 minutes. Behavioral, not one technical question or Brain Teaser.
3) Case Study and Interview. Two 45-minute interviews. First one you go over the Case Study, which you receive 4-5 days before the interview. I took a very analytical approach breaking down all the financial info. Spent 6-8 hours working on it before the interview and prepared 8 pages of notes on findings. They intentionally leave out information you'd need for any modeling or sophisticated analysis (Recent Financial Statements in my case). Made many assumptions which I explained and thought I impressed the VP.
Second interview was with another VP. Asked me three behavioral questions which took maybe 10 minutes. The other 35 minutes he asked "What questions do you have for me?". I had 5 questions prepared, so made up questions on the fly. It wasn't an interview, it was a conversation. Wish I could have shown knowledge of all the technical I prepared for. Was left confused and almost angry afterwards.
-Overall, was left confused. Was expecting technical which I spent weeks preparing for. All of it was useless.
-I'm nuts, and put about 40 hours into preparing in total for all the sections. (I needed this internship pretty bad, was my only open door)
Advice: Really, just be yourself. Pretty positive they take an average of your "scores" on each section. Don't make it seem like you tried too hard, I guess.
-Was told "We want to hire you guys, we need people" in a response to one of my questions and felt confident after the interviews. Was rejected 3 weeks later. I'm a humble dude, but was left confused after the fact. Thought I nailed it after all the prep I did. Hope the break down of the process helped. Only wrote this much because I spent hours on Glassdoor looking for advice and there wasn't much on the process and preparation going into the interview. Hope it helps.