McKinsey cases differ greatly? PrepLounge vs. Official

Hi,
Sharing this as a former McKinsey interviewer: the cases on the McKinsey website are 100% similar to what is asked in the interview process. McKinsey uses interviewer-led case style, where interviewer is trained to ask a questions to guide the discussion. You are expected to pause for 1-2 mins to structure your thoughts, but the interviewer kinda guides you through the case overall. For example, at first you're asked to share your overall approach to the problem. Then solve a specific math problem. Then look at a chart. Then another conceptual problem.
Prep loudge cases are good for building the overall case solving muscle. But McKinsey interview structure follows what is on the website.
Kateryna

The cases on McKinsey's website are simplified. They follow a clean structure: framework, exhibit, math. You don't need to ask questions or gather information. Everything is handed to you. These are designed to show candidates what a case looks like, not to fully replicate the real interview experience.

Real McKinsey interviews are more interactive. You'll need to ask clarifying questions, dig for information, and drive the conversation. The interviewer won't just hand you everything. You have to lead. There's also more back-and-forth, and the structure isn't always as neat as what you see online.

That said, McKinsey interviews do tend to be more interviewer-led than Bain or BCG. The interviewer often guides you through specific questions rather than letting you run completely free. But you still need to show initiative and ask smart questions along the way.

My advice: use the McKinsey website cases to understand the basics and get comfortable with exhibits and math. But don't rely on them alone. Practice with more interactive cases where you have to ask questions and gather information. That's closer to what you'll actually face.

Mix both styles in your prep. The real interview will land somewhere in between.

This is a fantastic question and hits on a real point of confusion. The truth is, the cases on the official McKinsey website are pedagogical tools—they are designed to be accessible and teach you the general flow and the types of logical jumps required (data analysis, math, synthesis). They are intentionally simplified.

The actual McKinsey interview dynamic, particularly for BA roles, is interviewer-led. It is a different beast than the classic, candidate-led PrepLounge case (which is often better preparation for BCG or Bain). You are generally not expected to spend five minutes structuring the entire problem or asking broad clarifying questions about the market before getting the first piece of data. The interviewer will guide you quickly from prompt to the first Exhibit, asking precise, targeted questions along the way.

What you should focus on is bridging the gap: The actual interviews follow the quick, structured progression you see on the website (Prompt → Exhibit → Question → Math → Synthesis), but they are much deeper, requiring rapid fire analysis and robust synthesis. The interviewer will constantly probe your logic, which is where the interactive PrepLounge practice becomes invaluable—not for structuring, but for practicing synthesizing charts and dealing with ambiguous data under pressure. Expect multiple, distinct math sections within one single case, all focused on interpreting provided data accurately.

If you are prepping for McKinsey, lean heavily into mastering the ability to analyze a complex chart or data table and immediately deliver a client-ready takeaway. That is the true differentiator.

Hope it helps!

Short answer:

The cases on the website give you a good idea of the type of problems that you can apply your mind to in the consulting environment, however, the rigor needed to demonstrate your problem solving may not be adequately assessed on such a setup.

Cases found on PrepLounge and other case libraries are more reflective of the actual working through of a case which allows sufficient exposure to all aspects of assessment including chart reading and insights generation. 

As a Real Madrid fan, the cases on the website are an orientation tour of the Bernabéu, however, the cases found elsewhere prepare you to play the game 

Hi there,

Both styles are relevant but the PrepLounge style is closer to real McKinsey BA interviews. The cases on McKinsey’s website are intentionally simplified and standardized to teach the format and reduce anxiety not to fully replicate the live interview experience.

In actual McKinsey interviews cases are typically interviewer led but you are still expected to ask clarifying questions request information and drive the analysis forward. You’ll usually move through multiple questions and may face more than one quantitative component in a case. The flow is often less linear and depends on how you perform and respond.

Think of the official McKinsey cases as a baseline for structure exhibit interpretation and synthesis. PrepLounge style cases better reflect the interactive nature of real interviews where judgment prioritization and communication matter as much as the math.

Best,
Evelina

hi there :)

I would say that McKinsey BA interviews, the style on PrepLounge is actually closer to real cases, they expect you to ask questions, structure your approach, and work through multiple math or analysis steps. The official website cases are simplified examples and don’t reflect the full interview dynamic. You can reach out anytime if you want guidance or realistic practice. 

I’ve been an interviewer and can run real McK-style cases with you.

best,
Alessa :)

Please check my cases on the PrepLounge library. 

They are as realistic as you can get to the sort of cases you will receive in a McK interview these days. 

And that's because they are based on actual interviews, then rewritten to protect IP. 

Best,
Cristian