Went through EY-Parthenon's interview process earlier this year for a senior associate role (post-MBA track). Sharing the full breakdown.
Round 1: Recruiter call, 30 min. Mostly logistics, why EY, salary expectations. Nothing hard.
Round 2: Behavioral interview with a manager. 45 min, 3 behavioral questions using their leadership framework. Questions were things like: a time you influenced without authority, a time you had to deliver difficult news to a client, and a time you changed direction mid-project. Classic. Prepare 5-6 strong STAR stories and you can hit all of these.
Round 3: Written case. 1 hour to review a client scenario doc, then 30 min to present findings to two interviewers. Not a live case. The scenario was a retail company considering an acquisition. They wanted a structured recommendation with supporting logic and risks. They pushed back hard on assumptions.
Round 4: Partner interview. 45 min. Half behavioral, half a strategic discussion on industry trends. The partner had strong opinions about where consulting is going post-AI. It was more of a conversation but you could feel how much weight it carried.
Total timeline: 5.5 weeks from application to verbal offer.
A few things that mattered: 1) Quantify your impact in behavioral answers. "I improved the process" won't land. "I reduced client reporting time by 40%" does. 2) Know EY's priorities in their current fiscal year. They publish a lot on this. Use it.
Good luck.