I helped a few candidates for similar positions.
With McKinsey (Energy practice):
- Cases in 3 out of 4 of the interviews
- Standard PEI
- Questions on leadership, creativity and motivation for joining
With BCG (Digital and Financial Services practices):
- Cases in 1 out of 5 of the interviews only, and high level (eg how would you organize a proposal for XYZ)
- Questions on how to organize growth for the new division
Some standard questions/topics you may expect are:
- Motivation for shifting from your current position/career path
- Examples of leading team/managing new divisions
- Example of managing difficult clients/stakeholders
- Sales experiences/customers you may bring
- Industry knowledge/experience in your area of specialization
Your interviewers will normally be principals or partners only.
If you need more help please PM me.