Cornerstone Research Case Interview: Complete Guide (2024)

Cornerstone Research case interview

Cornerstone Research case interviews are the most difficult part of the interview process. You will need to ace every single Cornerstone Research case interview in order to land a job offer.


Cornerstone Research case interviews are asked in every single round of interviews. Typically, there are two rounds of interviews at Cornerstone Research:


  • Cornerstone Research first round interview: Consists of case interviews and behavioral interview questions (e.g., tell me about a time when you led a team, give an example of a time you used data to solve a problem)


  • Cornerstone Research final round interview: Consists of case interviews and fit interview questions (e.g., why consulting, why Cornerstone Research)


If you have an upcoming interview with Cornerstone Research, we have you covered. In this article, we’ll cover exactly what you need to do to crush your Cornerstone Research case interview and land the job offer. In this article, we’ll cover:


  • What is a Cornerstone Research case interview?


  • What does a Cornerstone Research case interview assess


  • How to solve a Cornerstone Research case interview


  • Cornerstone Research case interview examples


  • Cornerstone Research case interview tips


  • Recommended Cornerstone Research case interview resources


If you’re looking for a step-by-step shortcut to learn case interviews quickly, enroll in our case interview course. These insider strategies from a former Bain interviewer helped 30,000+ land consulting offers while saving hundreds of hours of prep time.


What is a Cornerstone Research Case Interview?


Like most consulting firms, Cornerstone Research uses case interviews to assess candidates.


A case interview, also known as a “case” for short, is a 30 to 60-minute exercise in which you and the interviewer work together to develop a recommendation or answer to a business problem.


These business problems can be anything that real companies face:


  • How can Walmart increase its profitability?


  • What can Amazon do to increase customer retention?


  • How should Ford price its new electric vehicle?


  • Where should Disney open another Disneyland theme park?


Cornerstone Research case interviews simulate what the consulting job will be like by placing you in a hypothetical business situation. Cases simulate real business problems that Cornerstone Research solves for their clients. Many Cornerstone Research case interviews are based on actual projects that interviewers have worked on.


While consulting projects typically last between 3 to 9 months, Cornerstone Research case interviews condense solving the business problem into just 30 to 45 minutes.


Cornerstone Research case interviews can cover any industry, including retail, consumer packaged goods, financial services, energy, education, healthcare, government, and technology.


They can also cover a wide range of business situations, including entering a new market, launching a new product, acquiring a company, improving profitability, and growing revenues.


Although Cornerstone Research case interviews cover a wide range of industries and business situations, no technical or specialized knowledge is needed.


Nailing your Cornerstone Research case interviews is critical to getting a job offer. You will need to pass every single one of your Cornerstone Research case interviews.


What Does a Cornerstone Research Case Interview Assess?


Cornerstone Research case interviews assess five different qualities or characteristics: logical and structured thinking, analytical problem solving, business acumen, communication skills, and personality and cultural fit.


Logical and structured thinking: Consultants need to be organized and methodical in order to work efficiently.


  • Can you structure complex problems in a clear, simple way?


  • Can you take tremendous amounts of information and data and identify the most important points?


  • Can you use logic and reason to make appropriate conclusions?


Analytical problem solving: Consultants work with a tremendous amount of data and information in order to develop recommendations to complex problems.


  • Can you read and interpret data well?


  • Can you perform math computations smoothly and accurately?


  • Can you conduct the right analyses to draw the right conclusions?


Business acumen: A strong business instinct helps consultants make the right decisions and develop the right recommendations.


  • Do you have a basic understanding of fundamental business concepts?


  • Do your conclusions and recommendations make sense from a business perspective?


Communication skills: Consultants need strong communication skills to collaborate with teammates and clients effectively.


  • Can you communicate in a clear, concise way?


  • Are you articulate in what you are saying?


Personality and cultural fit: Consultants spend a lot of time working closely in small teams. Having a personality and attitude that fits with the team makes the whole team work better together.


  • Are you coachable and easy to work with?


  • Are you pleasant to be around?


All of these five qualities can be assessed in just a 30 to 60-minute case interview. This is what makes Cornerstone Research case interviews so effective in assessing consulting candidates.


How to Solve a Cornerstone Research Case Interview


There are generally six steps to solving a Cornerstone Research case interview. Step four and step five may happen in a different order depending on the case you receive, but all the other steps will occur in the same order each time.


1. Understand the case


Your Cornerstone Research case interview will begin with the interviewer giving you the case background information. While the interviewer is speaking, make sure that you are taking meticulous notes on the most important pieces of information. Focus on understanding the context of the situation and the objective of the case.


Don’t be afraid to ask clarifying questions if you do not understand something. You may want to summarize the case background information back to the interviewer to confirm your understanding of the case.


The most important part of this step is to verify the objective of the case. Not answering the right business question is the quickest way to fail a case interview.


2. Structure the problem


The next step is to develop a framework to help you solve the case. A framework is a tool that helps you structure and break down complex problems into smaller, more manageable components. Another way to think about frameworks is brainstorming different ideas and organizing them into different categories.


Before you start developing your framework, it is completely acceptable to ask the interviewer for a few minutes so that you can collect your thoughts and think about the problem.


Ideally, you want your framework to be as MECE as possible. MECE stands for mutually exclusive and collectively exhaustive. You want each element of your framework to have zero overlap with the other elements. Additionally, you want the sum of the elements of your framework to cover all of the important issues or areas of the case.


Once you have identified the major issues or areas that you need to explore, walk the interviewer through your framework. They may ask a few questions or provide some feedback.


For a complete guide on how to create tailored and unique frameworks for each case, check out our article on case interview frameworks.


3. Kick off the case


Once you have finished presenting your framework, you’ll start diving into different areas of your framework to begin solving the case. How this process will start depends on whether the case interview is candidate-led or interviewer-led.


If the case interview is a candidate-led case, you’ll be expected to propose what area of your framework to start investigating. So, propose an area and provide a reason for why you want to start with that area. There is generally no right or wrong area of your framework to pick first.


If the case interview is interviewer-led, the interviewer will tell you what area of the framework to start in or directly give you a question to answer.


Cornerstone Research case interviews are generally interviewer-led, but you may occasionally be given a candidate-led case.


4. Solve quantitative problems


Your Cornerstone Research case interview will most likely have some quantitative aspect to them. For example, you may be asked to calculate a certain profitability or financial metric. You could also be asked to estimate the size of a particular market or to estimate a particular figure.


The key to solving quantitative problems is to lay out a structure or approach upfront with the interviewer before doing any math calculations. If you lay out and present your structure to solve the quantitative problem and the interviewer approves of it, the rest of the problem is just simple execution of math.


When doing case interview math, make sure to talk through your thinking and calculations out loud. The interviewer should be able to easily follow what you are doing in each step of your calculations. Once you have calculated the answer, explain how your answer impacts the recommendation that you are beginning to form.


5. Answer qualitative questions


Your Cornerstone Research case interviews will likely also have qualitative aspects to them. You may be asked to brainstorm a list of potential ideas. You could also be asked to provide your opinion on a business issue or situation.


The key to answering qualitative questions is to structure your answer. When brainstorming a list of ideas, develop a structure to help you neatly categorize all of your ideas. When giving your opinion on a business issue or situation, provide a summary of your stance or position and then enumerate the reasons that support it.


When you finish answering a qualitative question, connect your answer back to the case objective. How does your answer impact the recommendation that you are beginning to form?


6. Deliver a recommendation


In the last step of the case interview, you’ll present your recommendation and provide the major reasons that support it. You do not need to recap everything that you have done in the case, so focus on only summarizing the facts that are most important.


It is also good practice to include potential next steps that you would take if you had more time or data. These can be areas of your framework that you did not have time to explore or lingering questions that you do not have great answers for.


Cornerstone Research Case Interview Examples


Cornerstone Research does not provide any case interview examples on their website. However, we’ve compiled all the Cornerstone Research case interviews we could find on job interview websites and forums.


Example #1: Imagine you're consulting for a major tech company accused of monopolistic practices in the online advertising industry. How would you approach analyzing the market structure, potential barriers to entry, and the company's market power?


Example #2: Suppose a pharmaceutical company is facing a patent infringement lawsuit related to one of its blockbuster drugs. How would you estimate the potential damages incurred by the plaintiff, considering factors such as lost profits and reasonable royalties?

Example #3: Let's say you're tasked with investigating allegations of securities fraud against a publicly traded company. How would you conduct a forensic analysis of financial statements and market data to identify potential irregularities or misrepresentations?


Example #4: A manufacturing company is being sued for environmental contamination caused by its operations. How would you assess the financial impact of potential cleanup costs, regulatory fines, and reputational damage on the company's overall valuation?


Example #5: In a class action lawsuit involving alleged price-fixing among several large retailers, how would you evaluate whether the case meets the criteria for class certification? What evidence would you look for to support or refute the existence of common questions of law or fact among class members?


Example #6: Suppose a private equity firm is considering acquiring a chain of luxury hotels. What factors would you analyze during the due diligence process to assess the target company's financial performance, competitive positioning, and potential synergies with the acquirer's existing portfolio?


Example #7: A software development company is seeking damages for patent infringement against a competitor. How would you determine the fair market value of the disputed patents, taking into account factors such as technological uniqueness, market demand, and licensing agreements?


Example #8: A financial services firm is under investigation for alleged violations of anti-money laundering regulations. What procedures would you recommend to assess the company's compliance controls, transaction monitoring systems, and remediation efforts to mitigate regulatory risks?


Example #9: In a class action lawsuit alleging false advertising claims against a food company, how would you design and conduct a consumer survey to measure the extent of consumer deception and quantify potential damages?


Example #10: A distressed retail chain is considering filing for Chapter 11 bankruptcy protection. As a financial advisor, what restructuring options would you propose to maximize the company's chances of survival, minimize creditor losses, and preserve stakeholder value?


Cornerstone Research Case Interview Tips


Below are our top ten tips for preparing for Cornerstone Research case interviews.


1. Start preparing early


Mastering Cornerstone Research case interviews takes time. Many of the skills and techniques needed to solve cases can’t be learned in just a day or in a week. Ideally, start preparing for your case interviews at least a month or two in advance to give yourself enough time to learn and practice.


2. Be consistent with what strategies you use


Whichever strategies you decide on using for Cornerstone Research case interviews, make sure that you are consistent in using them. The more you use the same strategies, the better and more comfortable you will get using them. On interview day, you’ll have confidence that these strategies will help you nail your case interviews.


3. Practice with a case partner


Practicing Cornerstone Research case interviews with a partner is the best way to simulate a real case interview. There are many aspects of cases that you won’t be able to work on if you are doing mock cases by yourself. Casing with a partner lets you practice your communication, presentation, and collaboration skills.


4. Keep a list of feedback from each case


You should keep a journal or log of all of the different pieces of feedback you get from your case interview partner during practice. This way, you’ll be able to identify trends and prioritize what improvement areas to focus on. For example, if you consistently receive feedback in each practice case that you need to structure your answers, that should be your top area to focus on.


5. Focus on improving one thing at a time


After doing some practice Cornerstone Research case interviews, you’ll likely have a long list of feedback and improvement areas. Try to focus on improving one thing at a time. Before each practice case, decide on the one thing that you really want to focus on and nail. This will be much more effective than trying to improve everything at once.


6. Make sure you understand the business problem and objective


The quickest way to fail a Cornerstone Research case interview is to answer or address the wrong business problem. Therefore, when the interviewer starts the case by reading the case background information, it is imperative that you identify what is the business problem and what is the primary question you are trying to answer. You should always verify the objective of the case with the interviewer.


7. Ask clarifying questions if needed


Don’t be afraid to ask clarifying questions. You will not be penalized for this. If there is a term that you are unfamiliar with, ask for the definition. If you don’t understand the objective of the case, ask questions to clarify this. If there is important information that you were not able to write down, ask the interviewer to repeat specific pieces of information.


All of these questions will help strengthen your understanding of the case situation and make it easier for you to solve the case.


8. Structure your approach before doing any math calculations


Before doing any math calculations, lay out an upfront approach or structure to walk the interviewer through what you are about to do. Developing a structure will help you avoid making unnecessary calculations or reaching a dead-end. If the interviewer approves of your approach, then the rest of the math problem is simple arithmetic.


9. Talk through your calculations out loud


Talking through your calculations out loud provides two benefits. One, it decreases the likelihood that you’ll make a mistake. Two, it makes it easier for the interviewer to follow what you are doing. If you happen to get stuck or make a mistake, the interviewer can jump in to offer suggestions or guidance. The interviewer cannot do this if you are not communicating exactly what you are doing.


10. Answer “so what?” after every question


When the interviewer asks you a quantitative or qualitative question during your Cornerstone Research case interview, don’t just answer it and stop there. After answering the question, ask yourself: “so what?” How does your answer help you solve the overall business problem? What implications does your answer have for your potential recommendation? You should be tying each answer that you give back to the case objective.


Recommended Cornerstone Research Case Interview Resources


Here are the resources we recommend to learn the most robust, effective case interview strategies in the least time-consuming way:


  • Comprehensive Case Interview Course (our #1 recommendation): The only resource you need. Whether you have no business background, rusty math skills, or are short on time, this step-by-step course will transform you into a top 1% caser that lands multiple consulting offers.


  • Hacking the Case Interview Book (available on Amazon): Perfect for beginners that are short on time. Transform yourself from a stressed-out case interview newbie to a confident intermediate in under a week. Some readers finish this book in a day and can already tackle tough cases.


  • The Ultimate Case Interview Workbook (available on Amazon): Perfect for intermediates struggling with frameworks, case math, or generating business insights. No need to find a case partner – these drills, practice problems, and full-length cases can all be done by yourself.



  • Behavioral & Fit Interview Course: Be prepared for 98% of behavioral and fit questions in just a few hours. We'll teach you exactly how to draft answers that will impress your interviewer