In terms of the group case I would consider the following:
- Your goal is to help the team to succeed, not to show you are better than any other team members (candidates who try to impress normally don’t receive offers)
- Befriend the other team members and bring a contribution; you should neither be dominant nor too quiet
- Take the leader role only if you feel natural in that role (ideally you should have some experience in that regard)
- If you are not the leader, support the natural leader with suggestions and activities required
- Help other team members to bring their contribution, asking their opinion
For the fit part, I would prepare on the standard questions:
- Tell me about yourself
- Why consulting
- Why Monitor Deloitte
- Give me an example when you led a team
- Tell me about a time when you had to convince someone not agreeing with you
- What has been your major achievement so far
- Why should we hire you
In terms of the partner rounds, their structure is the same as the standard case interviews (fit + case+ your questions); however, there is far more emphasis on communication and fit.
Specifically, the main difference you will find in a final round with partners is that at that stage they:
- spend more time on fit questions and your alignment with the company
- check more closely your communication (eg how you react to challenging questions)
- may not have a “proper” structured case to present – during my final at BCG I had one interview which was made by two market sizing questions and a brainteaser, without any business case. That's because at the final they know you can structure and crack a case (you passed 1 or 2 rounds already) and are more interested in your logic, personality and fit with the company
So in order to prepare for them I would concentrate on:
- Review in details your fit stories – they will probably matter more in partner rounds. In some finals I had almost exclusively behavioral questions
- Work on your communication (reaction under pressure, how to gain time when you do not have a structure ready, connect with the interviewer, etc). This is something you can test almost exclusively in p2p mocks with peers/experts.
- Prepare on cases as usual. More market sizing practice could be useful to think out of the box if you get unusual questions.
I helped several people for Monitor Deloitte and have a comprehensive list of the questions asked, in case you are interested to know more please feel free to PM me.