Interview First Aid
Case Cracking
Business Concepts
Every case-interview has a certain structure. An important factor on how your case interview is going to proceed is if the interview is interviewer-led or led by you – the candidate.
We’d like to explain the two interview formats – candidate-led cases and interviewer-led cases – highlight their differences, and provide you with tips on how to excel in each of them.
Interviewer-Led Cases
Interviewer-led cases are most frequently used at McKinsey. As the title suggests, the interviewer’s guidance through the case interview is firmer.
Would you like to try one of our interviewer-led cases right away? We have two exciting cases for you!
👉 Company case by accilium: School Bus Innovation
👉 PrepLounge case: Baby Clothing Market Entry
🔎 The following are a few indicators that hint towards interviewer-led cases:
- A very specific case question is posed.
- Either a lot of data will be given to you along with an initial breakdown of sub-problems or a broad problem may be given to you, and you would need to structure the problem by being as specific as possible.
- After structuring, the interviewer will ask you a set of pre-determined questions irrespective of what your structure is (this could be an abrupt move, so do not get nervous when this happens!)
- Interviewer-induced interruptions with turnarounds not resulting from the candidate’s analysis
- Lots of given data throughout the case, e.g. tables or graphs
- “What else” types of questions
- “Please explain more in detail” types of questions
McKinsey-style case interviews give the interviewer a more direct opportunity to test specific skills that the interviewer is interested in learning about you and assess areas of weaknesses.
💡 Remain in the driver's seat and beware of curveball questions
Despite the name of this case class, the candidate still needs to be the active leader of the overall case interview. Especially in interviewer-led cases, the largest fallacy is to become passive, unstructured, and driven by the interviewer. To lead the case, you need to be particularly structured. Be prepared for interruptions, and anticipate that they might disprove hypotheses or force you to develop a completely new framework.
- Keep the big picture in mind: Consider other problems or solutions if the interviewer suggests a hypothesis. These might be important later.
- Apply the MECE Principle: Structure your answers to be Mutually Exclusive and Collectively Exhaustive. This approach helps you be thorough and organized, avoiding random or unstructured ideas.
- Watch for curveball questions and stress tests: Be prepared for unexpected changes or time constraints. Stay calm and adapt as needed.
Candidate-Led Cases
In candidate-led cases, the interviewer expects the candidate to ‘lead’ her or him through the case. As the candidate, it is your responsibility to lead the case by asking relevant questions and also to develop and test your hypotheses. Candidate-led cases are the most common types of cases. You’ll encounter them at the majority of the big consulting firms such as BCG, Bain, and occasionally at McKinsey.
We've got candidate-led cases for you as well! Check out these two cases!
👉 Company case by INVERTO: VacuLuxe Innovations' Supply Chain Makeover
👉 PrepLounge case: Deep Water Rescue
🔎 A candidate-led case usually has the following characteristics:
- A very broad description of a situation
- A very general question or no question at all
- Complete freedom in terms of the approach and the structure
- Data and information is mostly provided at your request
As opposed to interviewer-led cases, it is harder for the interviewer to test specific abilities as the candidate defines what is investigated or talked about. On the other hand, you as the candidate need to be strong in defining and testing hypotheses. You need a clear roadmap in mind that allows you to ask targeted questions as opposed to randomly ‘bombarding’ your interviewer with random questions hoping for a lucky punch.
Be thorough and exceptionally structured. Here are some aspects to consider in a candidate-led case format:
- Form and share a hypothesis: Based on your questions, develop a hypothesis and test it with further questions. Communicate your hypothesis to the interviewer.
- Investigate thoroughly: Dive deep into your hypothesis to explore potential solutions. The interviewer may give subtle hints rather than direct guidance, so ask specific questions.
- Be exceptionally structured: In a candidate-led case, keep track of your data and focus on synthesis. Be prepared to adjust your argument as new information emerges. Good organization and thorough notes are crucial.
- Prepare for detail questions: Be ready to address important details that may not have been covered due to your chosen approach.
- Refine and test your hypothesis: Once you identify the key factor, revise your hypothesis and test it accordingly.
Key Takeaways
💡 Candidate-led cases are about your ability to ‘crack’ a broad problem
💡 Interviewer-led or McKinsey-style interviews are about being able to analyze the MECE way.
💡 You will most likely encounter a stressful moment. Always pause and think in a structured fashion.
🚀 Discover over 240 additional cases in our Case Library! Filter not only by style, but also by difficulty, company, type, and much more. Good luck solving them!
