I helped several people from non-business backgrounds, including former lawyers, to land into MBB. Answering your questions:
- if it is necessary to get courses in business in order to prepare for the interview. If so, what courses would you recommend?
Formally you don’t need any course, but an MBA may help to land an invitation.
Many candidates with law background make a transition into MBB doing an MBA first. However, if you manage to get an invitation, there is no need to do any course per-se (although some may help to develop business acumen).
In order to prepare for the interview itself, you can just work on cases and review the main concepts you may not be familiar with while doing them (eg NPV, breakeven, compound growth..). After 30 cases you should have a good idea of all the key terminology. If you find some industries are more challenging for you (eg financial services or mining) just try to do more cases related to them.
- how do legal professionals manage to succeed at these kind of interviews? What is expected from them ? Do we have to bring our legal knowledge to the table (during the case solving phase)?
The requirements are exactly the same as for any other candidate.
You should be able to pass the fit and the case parts, and show good communication skills (being a lawyer, I assume the latter won’t be a problem for you). You won’t need to bring any specific legal knowledge into the case, but you could use your experience to answer the fit questions at the beginning of the interview.
Please feel free to PM me for more information.