Consulting Case Interview 101

If you're planning to join top consulting firms like MBB (McKinsey, BCG, and Bain) or the Big Four (Deloitte, PwC, EY, and KPMG), the case interview is a critical part of the hiring process. For most people, cracking a case interview doesn’t come naturally—it requires focused preparation and lots of practice. Let’s dive into what case interviews are about and how to navigate them.

What is a Case Interview?

In a case interview, the interviewer presents you with a business problem and evaluates how you structure your thoughts, conduct analysis, and communicate your recommendations. It's designed to replicate real-life consulting scenarios, testing not just problem-solving but also how well you communicate and think on your feet.

What Key Skills Are MBB Testing in a Case Interview?

1. Analytical Thinking: Can you break a complex problem into smaller, logical components and tackle each effectively? This skill shows how structured and methodical your approach is.
2. Quantitative Skills: Do you understand the numbers? Can you analyze data, calculate metrics, and identify meaningful trends? It’s not just about doing the math—it’s about using it to support decisions.
3. Conceptual Thinking: Can you draw insights from your analysis and connect them to the bigger picture? This is about answering the critical “so what?” for the client and turning ideas into actionable recommendations.

Common Question Types in MBB Case Interviews

Framework Questions

These are usually the opening questions, like:

• “What factors would you consider to solve this problem?”
• “What should the team investigate to determine whether our client should enter the ABC market?”

A framework question asks you to build a logical roadmap for solving the client's problem. This isn’t about memorizing templates but creating a tailored structure based on the client’s needs.

What makes a strong framework:

• Comprehensive yet focused: Cover key areas but emphasize the ones that matter most to solving the problem.
• Well-reasoned and logical: Every factor you include should have a clear “why.” Back it up with logic.

Tip: A common mistake is listing too many factors without prioritizing or explaining them. Always focus on the most critical points and clarify how each fits into the problem-solving process.

Quantitative Questions

These focus on data analysis and calculations. Think of these as math problems with a story behind them. The math itself usually isn’t the hard part — what matters is explaining what the numbers mean.

Two keys to success:

• Clarity and speed: Work through your calculations methodically and explain your thought process.
• Insight-driven conclusions: Don’t stop at the answer. Show why the numbers matter and what they imply for the client.

Conceptual Questions

These are brainstorming-style questions, such as:

• “What risks would you consider when entering a new market?”
• “How might changes in customer behaviour affect the business?”

They test how well you can think critically and creatively while staying structured.

What to focus on:

• Structured creativity: Your response should be logical and actionable, not vague or generic.
• Industry context: You don’t need deep industry knowledge, but adding relevant context or brilliant insights will make your answers stand out.

Chart Interpretation

In these questions, you’ll analyze a graph or table and respond to “What do you think?”

Two key steps:

• Spot trends: Identify the main patterns or anomalies in the chart.
• Draw implications: Connect the dots between the charts and what they mean for the client or problem.

Example: Imagine you’re given a chart showing a drop in profit margins for a retailer. You could highlight the declining trend and hypothesize possible causes—such as rising supplier costs or increased competition. Then, suggest areas for further investigation, like renegotiating contracts or evaluating pricing strategies.

Two Main Styles of Case Interviews

Candidate-Led Cases

This style of case interviews is commonly used at BCG and Bain. Here, you take the lead. The interviewer presents the problem, and you decide what to ask, where to dig deeper, and how to structure the analysis. The interviewer only provides additional data or hints if you ask the right questions—or if you’re veering off track and need guidance.

Time management is critical in this format. Spend too long on one part, you might not finish. Stay focused, prioritize the most important areas, and keep your analysis moving.

Interviewer-Led Cases

In this format, the interviewer controls the flow. They’ll ask you 3 to 5 structured questions, typically starting with a framework, and then moving on to chart interpretation, math, and brainstorming. This style is standard at McKinsey and used in most written cases.

Typical Case Interview Structure (30-45 Minutes)

Step	Duration
*McKinsey doesn’t require final recommendation
Introduction and small talk	2-5 minutes
Problem prompt and clarification	<5 minutes
Framework setup	~10 minutes
Chart interpretation and quantitative analysis	~10 minutes
Brainstorming question	5-10 minutes
Final recommendation*	<5 minutes