Consulting Written Case Interviews: A Complete Guide

Written case interviews are a key part of the consulting recruitment process. If you're aiming to land a job at a top consulting firm, understanding how to ace these interviews is crucial. They evaluate your ability to think critically, manage complex data, and present your ideas clearly. Unlike traditional interviews, where you might speak directly with an interviewer, a written case challenges you to analyze data and present your findings in writing—skills that are essential for a consultant.

In this article, we'll walk you through what to expect in written case interviews, how to prepare, and what strategies will help you succeed. Whether you're just starting your preparation or looking to refine your skills, this guide will give you the insights and tips you need to shine in your interview.

Understanding Written Case Interviews

Definition and Purpose

A written case interview is designed to test your problem-solving abilities, analytical thinking, and communication skills—all of which are critical in consulting. Think of it as a challenge where you're asked to solve a real business problem, analyze large datasets, and present your recommendations clearly and concisely.

For example, imagine you're working with McKinsey, and they give you a case about analyzing market entry strategies for a multinational firm. You’ll be expected to quickly make decisions, assess the competitive landscape, and present your recommendations in a logical and clear way. This case tests your ability to process information efficiently and communicate it effectively, just like you would need to do on the job.

Firm-Specific Formats

Different consulting firms have their own unique approach to written case interviews, so it’s important to understand what each one typically asks. This way, you can tailor your preparation to match the firm’s expectations.

Take BCG, for instance. In their written case interviews, you might be asked to analyze a profitability problem for a retail client. You could be given a range of data—from sales trends to cost structures—and need to come up with actionable solutions for boosting profitability. It’s a great way for them to see how well you can work with numbers and data, so brushing up on data interpretation is key.

On the other hand, Bain’s written cases often involve strategic recommendations, like advising a company on entering a new market. Here, you’ll need to consider factors like market trends, consumer behavior, and competitor strategies, combining both qualitative and quantitative analysis. Bain tends to look for a balanced approach that combines strategic thinking with solid data analysis.

Each firm has its own style, and understanding these nuances will help you feel more prepared and confident on the day of your interview. By knowing what to expect, you can focus your preparation on the specific skills and approaches that are most important to each company.

Preparation Strategies

Time Management

When you're tackling a written case interview, time is one of your most valuable resources. Without managing it properly, it’s easy to feel rushed or overwhelmed. That’s why it’s important to break the time into manageable chunks. A strategy shared by a former Bain candidate could be your secret weapon: they spent 40% of their time analyzing data, 30% on structuring their presentation, and the remaining 30% on refining their solution. This approach helped them stay focused on the most important parts of the case, while ensuring the final presentation was clear and well-polished.

Try adopting a similar breakdown for your own preparation. Start by dedicating time to analyze the case and dig into the data. Then, move on to structuring your solution and creating your presentation. Finally, leave enough time at the end to review and refine everything. By following this approach, you’ll make sure that each step gets the attention it deserves without feeling rushed.

Information Prioritization

You’ll often be given a lot of data in a written case interview, and it’s crucial to know how to quickly identify the most relevant pieces. The ability to prioritize the right information will help you avoid getting lost in unnecessary details and keep you on track to solving the client’s problem.

Imagine you’re working on a case to improve operational efficiency for a manufacturing client. You might receive data on production costs, employee satisfaction, and market trends. While all of this information is useful, not everything will be directly related to your solution. For example, focusing on cost reduction and process optimization will likely have a bigger impact than spending time on employee satisfaction unless it’s clearly tied to the solution.

Being able to sort through this data and focus on what truly matters is one of the key skills you’ll need. It allows you to stay focused and make smarter decisions about where to direct your energy and attention.

Slide Design

Once you’ve analyzed the data and come up with your recommendations, you need to present your findings in a clear and effective way. This is where your slide design comes in. Simple, well-organized slides are essential to help your interviewer follow your logic and easily understand your key insights.

For example, in a BCG case on market expansion, a candidate used slides that highlighted market share data and projected revenues. Each slide had a clear, descriptive title, and the visuals (like charts) made it easy for the interviewer to grasp the important takeaways quickly. By keeping the design simple and focused on key points, the candidate ensured that their ideas were communicated clearly and effectively.

When designing your slides, keep these tips in mind:

• Use clear, descriptive titles that guide the reader through your points.
• Incorporate visuals, like charts or graphs, to make data more digestible.
• Keep text minimal—focus on the most important takeaways.
• Ensure your slides flow logically, so the story is easy to follow.

By sticking to these principles, your slides will complement your analysis and help you communicate your ideas in a way that’s both clear and impactful.

Analytical Approach

Issue Trees

When you’re faced with a complex case, breaking it down into smaller, more manageable pieces is essential. This is where issue trees come in. They’re a simple yet powerful tool that helps you organize your thinking and structure your analysis.

Imagine you’re tackling a case about cutting costs for a retail company. An issue tree could help you categorize costs into broad groups like operations, supply chain, and labor. Then, you can break each category down into smaller components—like examining store management practices under “operations” or looking into shipping costs and inventory management under “supply chain.”

Using an issue tree helps you stay organized, ensuring you don’t miss any important areas to explore. It also allows you to approach the problem from different angles, making sure you consider all possible solutions. By mapping things out visually, you’ll have a clearer view of the situation and be able to make more informed decisions.

Data Interpretation

Once you’ve broken the problem down, the next step is diving into the data. The key here is not just looking at numbers but understanding what they’re really telling you.

Let’s take a real example from McKinsey: You’re given sales figures for a chain of restaurants and tasked with figuring out what’s affecting profitability. Through careful analysis, you might notice that restaurants in high-traffic areas are performing much better than those in more isolated locations. This simple insight can make all the difference in your recommendations.

Instead of suggesting a broad cost-cutting plan, you could recommend focusing on opening new branches in high-traffic areas, where there’s a clear correlation with higher sales. Properly interpreting the data isn’t just about crunching the numbers—it’s about seeing the story behind them and applying those insights to create practical, targeted solutions.

Crafting the Presentation

Executive Summary

Your executive summary is your opportunity to grab the interviewer's attention right from the start. It’s a brief but powerful part of your presentation that sets the stage for everything that follows. The key is to keep it simple but impactful, summarizing the problem, your analysis, and the solutions all in one go.

For example, a former BCG candidate kicked off their presentation with an executive summary that immediately addressed the client’s concern about profitability. They recommended three strategic actions—cost reductions, pricing adjustments, and expanding product offerings—all supported by solid data and insights. This not only made it clear what the main issue was, but it also showed that they had a plan to tackle it.

When you write your own executive summary, think of it as your roadmap. It should quickly give the interviewer an overview of the situation, the actions you recommend, and the reasoning behind those actions. This helps the interviewer know what to expect and gives them confidence in your approach from the outset.

Logical Flow

Once you've nailed your executive summary, the next step is to make sure your presentation flows logically. You want the interviewer to be able to follow your thought process easily, so your ideas should build on each other in a natural way.

Take a McKinsey case, for instance. In a case about declining market share, a candidate started by identifying the root causes, then presented three possible solutions, each backed by data. The candidate didn’t just offer solutions—they showed the feasibility, costs, and benefits of each option. This clear progression helped the interviewer understand how the recommendations were tied directly to the problem.

For your presentation, here’s how to structure the flow:

• Start with a clear restatement of the problem and a quick overview of your analysis.
• Move into your recommendations, presenting each one with data and support.
• Wrap up by explaining the trade-offs between each option, so the interviewer can see that you've considered all angles.

By keeping your presentation logically structured, you’ll ensure that the interviewer can easily follow along with your reasoning, making it easier for them to buy into your recommendations.

Common Pitfalls to Avoid

Overloading Slides

It can be tempting to cram as much information as possible into your slides, thinking that more is better. But the truth is, too much information can actually hurt your presentation. The key is to focus on clarity, not quantity.

For example, in a Bain case, a candidate made the mistake of putting too many ideas on a single slide. It ended up overwhelming the interviewer and making it hard to pinpoint the key takeaways. The lesson here is simple: prioritize clarity. You want your slides to showcase the most important insights, not everything you've analyzed.

Here's what you can do to avoid this pitfall:

• Focus each slide on one core message.
• Use visuals like charts or graphs to make your points easier to understand.
• Keep text short and to the point—bullet points work better than long paragraphs.

By keeping your slides clean and simple, you’ll help the interviewer stay focused on your key points, making your analysis stronger and easier to follow.

Neglecting Assumptions

When you’re working through a case, you’ll often need to make assumptions. That’s perfectly normal, but it’s crucial to be upfront about them. If you’re assuming things like market conditions or regulatory stability, you need to clearly state those assumptions and explain why you made them.

For instance, a candidate working on a market entry strategy for an automotive brand assumed that the local regulatory environment would remain stable, which influenced their recommendations. However, they didn’t clearly communicate this assumption, which could have caused confusion or left the interviewer questioning their conclusions.

To avoid this mistake:

• Always state your assumptions clearly.
• Justify why those assumptions make sense based on the data or context.
• Be ready to adjust your recommendations if those assumptions change.

Being transparent about your assumptions not only builds credibility but also shows that you've thought critically about the problem and the potential risks involved.

Post-Interview Reflection

Self-Assessment

Once the interview is over, don’t rush into the next task without taking a step back. Reflecting on your performance is key to improving for next time. This isn’t just about recognizing what went well; it’s about understanding where you can do better and how you can refine your approach for the future.

For example, a former McKinsey candidate shared how, after their interview, they took the time to review and realized they could improve how they communicated data-driven insights. Although they analyzed the data correctly, they felt their explanation could have been clearer. This reflection helped them adjust their approach for future interviews, making them more confident in their ability to communicate complex ideas.

By assessing your own performance, you’ll gain valuable insights into what worked, what didn’t, and how you can improve for the next round.

Continuous Improvement

Self-reflection is just the first step—now it’s time to keep improving. The most successful consultants don’t stop at just one practice session. They continually seek feedback, practice regularly, and make refining their skills a habit.

To keep improving:

• Ask for feedback from people who can give you constructive criticism—peers, mentors, or even coaches.
• Keep practicing with different case studies to challenge yourself in new ways.
• Focus on areas where you feel less confident, and push yourself to refine those skills.

By making practice and feedback a regular part of your routine, you’ll continue to grow and fine-tune your case interview skills, setting yourself up for success in future interviews.