Thank you for the question! My best recommendation is absolutely practice practice practice :) I went through several case interview prep books and articles (like the famous Case In Point or Victor Cheng’s guides) to understand how the case interview works, what to expect and what frameworks might be helpful. I drew out the most relevant frameworks for myself to think about how they can be helpful to me. And most importantly, I practiced a lot. I did about 30 written cases by myself and about 20 live cases with my friends – especially those who had gone through consulting interviews themselves were the greatest help. Practice really helps you get your nerves in check, familiarize with the routines and also just improve your problem solving skills with every new scenario you encounter – I saw improvements with every singe practice case I did.

How did you prepare for your case interview? Any tips?

Practise is key when it comes to case studies. There are a number of good ressources online that you can access (for free) in order to get a good backlog of case studies. Then I would suggest to just work through them. Classical consulting frameworks can help you structure your answers but don't let them limit your solution path.
Moreover, It is always valuable to discuss your solution with peers to get an idea for other possible approaches to a problem. Often there is not just one right way to solve a case study and interviewers are aware of that. Try to think of case studies as a chance to show your thought process and how you appraoch problems.
I did various case studies prior to the presentation - there are many examples online as well as in books. I can also recommend presenting the result of the case study to friends or family in order to practice your presentation skills. This will help you to improve from time to time and you learn on which aspects you have to focus!

