Did both rounds at a US office last October. Eight interviews total across two days, each with a case plus PEI. I had prepped cases for months so the cases themselves weren't what got me, but the PEI depth genuinely surprised me.
First round interviewer picked a leadership story I mentioned in passing and spent 20 minutes on that one story. Not asking for new examples. Just drilling: what did you specifically say in that meeting, who pushed back, what did you do when the client disagreed. If your stories are thin, that style of questioning exposes it fast.
The cases were on the easier end of what I expected for R1. Market sizing, profitability. R2 had a full private equity due diligence scenario that was more ambiguous. They weren't looking for the right answer. They were watching how I handle a wrong turn, whether I notice it, whether I recalibrate without prompting.
One thing I didn't expect: both rounds had a "get to know you" five minutes at the start that matters. Not chit-chat. They're watching whether you're someone they'd be comfortable putting in front of a client. Be real but be pulled-together.
Got an offer. Happy to answer questions.