Case Interviews are becoming increasingly common, as they are used beyond just Management Consulting interviews, and are now a staple of Product Management, Finance, Analytics, and many other job interviews. There are some common types of case questions, ranging from profitability cases to design a solution for Problem X, but often these prompts are becoming more ambiguous and varied, which means memorizing a standard set of frameworks will not be enough, nor will it differentiate you from the competition. Instead, it is important to to build the problem solving muscle, so you develop the cognitive skills to break down any case prompt, and thoughtfully tackle each component in a structured, analytical, and cohesive manner.   The following will guide you on strategies you can use to prepare for the now ubiquitous case interview.
WHAT NOT TO DO. First let’s go over the checklist of what not do.  You should avoid the following:
  • Re-stating the prompt, verbatim from your notes.  While it is good practice to synthesize the prompt to ensure clarity, too often candidates simply re-state what is already obvious.
  • Asking for assumptions.  This is your opportunity to demonstrate your problem solving, so it is better to state your assumptions as you walk through the problem,  giving the interviewer a window into your thinking, and an opportunity to pressure test your assumptions.
  • Apply an “off the shelf” framework, without tailoring or including nuance that shows you understand the problem deeply, rather than just demonstrating your memorization skills.
Your questions should be as unique as your qualifications.
SO, WHAT SHOULD YOU DO? Here are 5 techniques you should use to ace the case interview. 1.  Ask for a moment to structure your thoughts. In management consulting interviews, for example with McKinsey and Company, it is standard to ask for 1-2 minutes to outline a structure before you dive into problem solving. For other disciplines such as product management and finance, the depth and ambiguity of the question will drive the need to take time before you dive in, so if it does take some time to process then ask for the time, and even if they would rather you just jump in they will not dock you points for asking for a moment. It is more effective to present a thoughtful and structured response than to demonstrate speed at the expense of a quality answer.
2.  Outline your structure before you go into the details Let’s take an example – the Facebook Product Manager Interview – and let us take a common case question:  “How would you figure out why product X has had declining monthly active users?” Before you take on aspect of the answer, for example the usefulness of the feature, you first want to outline all the areas you will analyze.  This shows the interviewer your holistic thinking, before you go too deep, and also allows the interviewer to guide you in the areas they want to explore with you, making for a more meaningful dialogue. In this example question, you might outline the following as the areas you would analyze
  • Instrumentation:  Ensure the data is indeed accurate and that the tools and process to measure the data has not changed.
  • User segments:  Disaggregate the decline by user segments to see if this impacts different cohorts by geography, device type, demographics, etc.
  • Competition:  Identify any changes (e.g., new product releases) in the ecosystem of adjacent and similar products.
  • Other Features:  Analyze other changes within the suite of products that could be impacting this feature.  Maybe another product or features has increased usage that is shifting user engagement patterns.
3.  Identify high leverage variables After you have holistically structured the areas to analyze, you want to start to highlight the areas you think might matter the most so you can demonstrate having a point of view, and not just tackling the problem from an academic point of view. For example, if the question is about declining revenue, and you understand that the business hinges on repeat store visits, more than it does on average basket size, then you can note that to take your problem solving to the next level by showing you can grasp the business context of the problem.
4.  Externalize your logic Think of this exercise as connecting the dots between many facets of a problem, and not as a checklist exercise where you get points for listing the most ideas.  For example, if you note wanting to evaluate the competitive landscape to understand why customer repeat visits are declining, it is good practice to highlight what it is you want to know about the competitive landscape and why.  In this case, maybe your hypothesis is that competitors have reduced prices and demand is elastic, or that they have introduced new products, or new incentives. Whatever the rationale, the more you can articulate that as you describe the areas you want to analyze, the more the interviewer will understand the sophistication of your thinking.  Moreover, they can also help guide you if they clearly understand your thought process.
5.  Synthesize your findings and insights Case questions can go in many directions, and you gather disparate pieces of information along the way, so occasionally synthesizing what you know so far as you progress through the case, can help converge towards an answer or at least a prioritized framework to solve the problem, while also showing your ability to bring cohesion and unity to complex situations with many variables.
Summary Remember, when faced with a case interview question, it is more important to demonstrate your approach to problem solving and elucidate your thought process, than it is to quickly or mechanically try and solve the case.