Case Interview: A comprehensive guide

3. Types of case interview

While most case interviews share a similar structure, firms will have some differences in the particular ways they like to do things in terms of both the case study and the fit component.

As we’ll see, these differences aren’t hugely impactful in terms of how you prepare. That said, it's always good to know as much as possible about what you will be going up against.

3.1. Different case objectives

A guiding thread throughout this article and our approach in general will be to treat each case as a self-contained problem and not try to pigeonhole it into a certain category. Having said that, there are of course similarities between cases and we can identify certain parameters and objectives.

Broadly speaking, cases can be divided into issue-based cases and strategic decision cases. In the former you will be asked to solve a certain issue, such as declining profits, or low productivity whereas in the latter you will be ask whether your client should or should not do something, such as enter a specific market or acquire another company. The chart below is a good breakdown of these different objectives:

3.2. How do interviewers craft cases

While interviewers will very likely be given a case bank to choose from by their company, a good number of them will also choose to adapt the cases they would currently be working on to a case interview setting. The difference is that the latter cases will be harder to pigeonhole and apply standard frameworks to, so a tailored approach will be paramount.

If you’ve applied for a specific practice or type of consulting - such as operational consulting, for example - it’s very likely that you will receive a case geared towards that particular area alongside a ‘generalist’ consulting case (however, if that’s the case, you will generally be notified). The other main distinction when it comes to case interviews is between interviewer-led and candidate-led.

3.3. Candidate-led cases

Most consulting case interview questions test your ability to crack a broad problem, with a case prompt often going something like:

"How much would you pay to secure the rights to run a restaurant in the British Museum?"

You, as a candidate, are then expected to identify your path to solve the case (that is, provide a structure), leveraging your interviewer to collect the data and test your assumptions.

This is known as a “candidate-led” case interview and is used by Bain, BCG and other firms. From a structuring perspective, it’s easier to lose direction in a candidate-led case as there are no sign-posts along the way. As such, you need to come up with an approach that is both broad enough to cover all of the potential drivers in a case but also tailored enough to the problem you are asked to solve. It’s also up to you to figure out when you need to delve deeper into a certain branch of the case, brainstorm or ask for data. The following case from Bain is an excellent example on how to navigate a candidate-led case.

3.4. Interviewer-led cases

This type of case - employed most famously by McKinsey - is slightly different, with the interviewer controlling the pace and direction of the conversation much more than with other case interviews.

At McKinsey, your interviewer will ask you a set of pre-determined questions, regardless of your initial structure. For each question, you will have to understand the problem, come up with a mini structure, ask for additional data (if necessary) and come to the conclusion that answers the question. This more structured format of case also shows up in online cases by other firms - notably including BCG’s Casey chatbot (with the amusing result that practising McKinsey-style cases can be a great addition when prepping for BCG).

Essentially, these interviewer-led case studies are large cases made up of lots of mini-cases. You still use basically the same method as you would for standard (or candidate-led) cases - the main difference is simply that, instead of using that method to solve one big case, you are solving several mini-cases sequentially. These cases are easier to follow as the interviewer will guide you in the right direction. However, this doesn’t mean you should pay less attention to structure and deliver a generic framework! Also, usually (but not always!) the first question will ask you to map your approach and is the equivalent of the structuring question in candidate-led cases. Sometimes, if you’re missing key elements, the interviewer might prompt you in the right direction - so make sure to take those prompts seriously as they are there to help you get back on track (ask for 30 seconds to think on the prompt and structure your approach). Other times - and this is a less fortunate scenario - the interviewer might say nothing and simply move on to the next question. This is why you should put just as much thought (if not more) into the framework you build for interviewer-led cases, as you may be penalized if you produce something too generic or that doesn’t encompass all the issues of the case.

3.5. Case and fit

The standard case interview can be thought of as splitting into two standalone sub-interviews. Thus “case interviews” can be divided into the case study itself and a “fit interview” section, where culture fit questions are asked.

This can lead to a bit of confusion, as the actual case interview component might take up as little as half of your scheduled “case interview”. You need to make sure you are ready for both aspects.

To illustrate, here is the typical case interview timeline:

1. First 15-30 minutes: Fit Interview - with questions assessing your motivation to be a consultant in that specific firm and your traits around leadership and teamwork. Learn more about the fit interview in our in-depth article here.
2. Next 30-40 minutes: Case Interview - solving a case study
3. Last 5 minutes: Fit Interview again - this time focussing on your questions for your interviewer.

Both the Case and Fit interviews play crucial roles in the finial hiring decision. There is no “average” taken between case and fit interviews: if your performance is not up to scratch in either of the two, you will not be able to move on to the next interview round or get an offer.

3.6. What is different in 2024?

For the foreseeable future, you are going to have to go through multiple live case interviews to secure any decent consulting job. These might increasingly happen via Zoom rather than in person, but they should remain largely the same otherwise.

However, things are changing and the rise of AI in recent months seems pretty much guaranteed to accelerate existing trends.

Even before the explosive development of AI chatbots like ChatGPT we have seen in recent months, automation was already starting to change the recruitment process.

As we mentioned, case interviews are expensive and inconvenient for firms to run. Ideally, then, firms will try to reduce the number of interviews required for recruitment as far as possible. For many years, tests of various kinds served to cut down the applicant pool and thus the number of interviews. However, these tests had a limited capacity to assess candidates against the full consulting skillset in the way that case interviews do so well.

More recently, though, the development of online testing has allowed for more and more advanced assessments. Top consulting firms have been leveraging screening tests that better and better capture the same skillset as case interviews. Eventually this is converging on automated case studies. We see this very clearly with the addition of the Redrock case to McKinsey’s Solve assessment.

As these digital cases become closer to the real thing, the line between test and case interview blurs. Online cases don’t just reduce the number of candidates to case interview, but start directly replacing them.

Case in point here is BCG’s Casey chatbot. Previously, BCG had deployed less advanced online cases and similar tests to weed out some candidates before live case interviews began. Now, though, Casey actually replaces one first round case interview.

Casey, at time of writing, is still a relatively “basic” chatbot, basically running through a pre-set script. The Whatsapp-like interface does a lot of work to make it feel like one is chatting to a “real person” - the chatbot itself, though, cannot provide feedback or nudges to candidates as would a human interviewer.

We fully expect that, as soon as BCG and other firms can train a truer AI, these online cases will become more widespread and start replacing more live interviews.

We discuss the likely impacts of advanced AI on consulting recruitment and the industry more broadly in our blog.

Here, though, the real message is that you should expect to run into digital cases as well as traditional case interviews.

Luckily, despite any changes in specific case interview format, you will still need to master the same fundamental skills and prepare in much the same way.

We’ll cover a few ways to help prepare for chatbot cases in section four. Ultimately, though, firms are looking for the same problem solving ability and mindset as a real interviewer. Especially as chatbots get better at mimicking a real interviewer, candidates who are well prepared for case cracking in general should have no problem with AI-administered cases.

4. How to solve cases with the Problem-Driven Structure?

If you look around online for material on how to solve case studies, a lot of what you find will set out framework-based approaches. However, as we have mentioned, these frameworks tend to break down with more complex, unique cases - with these being exactly the kind of tough case studies you can expect to be given in your case interviews.

To address this problem, the MyConsultingCoach team has synthesized a new approach to case cracking that replicates how top management consultants approach actual engagements.

MyConsultingCoach’s Problem Driven Structure approach is a universal problem solving method that can be applied to any business problem, irrespective of its nature.

As opposed to just selecting a generic framework for each case interview, the Problem Driven Structure approach works by generating a bespoke structure for each individual question and is a simplified version of the roadmap McKinsey consultants use when working on engagements.

The canonical seven steps from McKinsey on real projects are simplified to four for case interview questions, as the analysis required for a six-month engagement is somewhat less than that needed for a 45-minute case study. However, the underlying flow is the same (see the method in action in the video below)

Let's zoom in to see how our method actually works in more detail:

4.1. Identify the problem

Identifying the problem means properly understanding the prompt/question you are given, so you get to the actual point of the case.

This might sound simple, but cases are often very tricky, and many candidates irretrievably mess things up within the first few minutes of starting. Often, they won’t notice this has happened until they are getting to the end of their analysis. Then, they suddenly realise that they have misunderstood the case prompt - and have effectively been answering the wrong question all along!

With no time to go back and start again, there is nothing to do. Even if there were time, making such a silly mistake early on will make a terrible impression on their interviewer, who might well have written them off already. The interview is scuppered and all the candidate’s preparation has been for nothing.

This error is so galling as it is so readily avoidable.

Our method prevents this problem by placing huge emphasis on a full understanding of the case prompt. This lays the foundations for success as, once we have identified the fundamental, underlying problem our client is facing, we focus our whole analysis around finding solutions to this specific issue.

Now, some case interview prompts are easy to digest. For example, “Our client, a supermarket, has seen a decline in profits. How can we bring them up?”. However, many of the prompts given in interviews for top firms are much more difficult and might refer to unfamiliar business areas or industries. For example, “How much would you pay for a banking license in Ghana?” or “What would be your key areas of concern be when setting up an NGO?”

Don’t worry if you have no idea how you might go about tackling some of these prompts!

In our article on identifying the problem and in our full lesson on the subject in our MCC Academy course, we teach a systematic, four step approach to identifying the problem, as well as running through common errors to ensure you start off on the right foot every time!

This is summarised here:

Following this method lets you excel where your competitors mess up and get off to a great start in impressing your interviewer!

4.2. Build your problem driven structure

After you have properly understood the problem, the next step is to successfully crack a case is to draw up a bespoke structure that captures all the unique features of the case.

This is what will guide your analysis through the rest of the case study and is precisely the same method used by real consultants working on real engagements.

Of course, it might be easier here to simply roll out one an old-fashioned framework, and a lot of candidates will do so. This is likely to be faster at this stage and requires a lot less thought than our problem-driven structure approach.

However, whilst our problem driven structure approach requires more work from you, our method has the advantage of actually working in the kind of complex case studies where generic frameworks fail - that is exactly the kind of cases you can expect at an MBB interview.

Since we effectively start from first principles every time, we can tackle any case with the same overarching method. Simple or complex, every case is the same to you and you don’t have to gamble a job on whether a framework will actually work

In practice, structuring a problem with our method means drawing up either an issue tree or an hypothesis tree, depending on how you are trying to address the problem.

4.2. Lead the analysis

A problem driven structure might ensure we reach a proper solution eventually, but how do we actually get there?

We call this step "leading the analysis", and it is the process whereby you systematically navigate through your structure, identifying the key factors driving the issue you are addressing.

Generally, this will mean continuing to grow your tree diagram, further segmenting what you identify as the most salient end nodes and thus drilling down into the most crucial factors causing the client’s central problem.

Once you have gotten right down into the detail of what is actually causing the company’s issues, solutions can then be generated quite straightforwardly.

To see this process in action, we can return to our airline revenue example:

Let’s say we discover the average ticket price to be a key issue in the airline’s problems. Looking closer at the drivers of average ticket price, we find that the problem lies with economy class ticket prices. We can then further segment that price into the base fare and additional items such as food.

Having broken down the issue to such a fine-grained level and considering the 80/20 rule(see below), solutions occur quite naturally. In this case, we can suggest incentivising the crew to increase onboard sales, improving assortment in the plane, or offering discounts for online purchases.

Our article on leading the analysis is a great primer on the subject, with our video lesson in the MCC Academy providing the most comprehensive guide available.

4.4. Provide recommendations

So you have a solution - but you aren’t finished yet!

Now, you need to deliver your solution as a final recommendation.

This should be done as if you are briefing a busy CEO and thus should be a one minute, top-down, concise, structured, clear, and fact-based account of your findings.

The brevity of the final recommendation belies its importance. In real life consulting, the recommendation is what the client has potentially paid millions for - from their point of view, it is the only thing that matters.

In a case interview, your performance in this final summing up of your case is going to significantly colour your interviewer’s parting impression of you - and thus your chances of getting hired!

So, how do we do it right?

Barbara Minto's Pyramid Principle elegantly sums up almost everything required for a perfect recommendation. The answer comes first, as this is what is most important. This is then supported by a few key arguments, which are in turn buttressed by supporting facts.

Across the whole recommendation, the goal isn’t to just summarise what you have done. Instead, you are aiming to synthesize your findings to extract the key "so what?" insight that is useful to the client going forward.

All this might seem like common sense, but it is actually the opposite of how we relay results in academia and other fields. There, we typically move from data, through arguments and eventually to conclusions. As such, making good recommendations is a skill that takes practice to master.

We can see the Pyramid Principle illustrated in the diagram below:

To supplement the basic Pyramid Principle scheme, we suggest candidates add a few brief remarks on potential risks and suggested next steps. This helps demonstrate the ability for critical self-reflection and lets your interviewer see you going the extra mile.

The combination of logical rigour and communication skills that is so definitive of consulting is particularly on display in the final recommendation.

Despite it only lasting 60 seconds, you will need to leverage a full set of key consulting skills to deliver a really excellent recommendation and leave your interviewer with a good final impression of your case solving abilities.

Our specific article on final recommendations and the specific video lesson on the same topic within our MCC Academy are great, comprehensive resources. Beyond those, our lesson on consulting thinking and our articles on MECE and the Pyramid Principle are also very useful.

4.5. What if I get stuck?

Naturally with case interviews being difficult problems there may be times where you’re unsure what to do or which direction to take. The most common scenario is that you will get stuck midway through the case and there are essentially two things that you should do:

• 1. Go back to your structure
• 2. Ask the interviewer for clarification

Your structure should always be your best friend - after all, this is why you put so much thought and effort into it: if it’s MECE it will point you in the right direction. This may seem abstract but let’s take the very simple example of a profitability case interview: if you’ve started your analysis by segmenting profit into revenue minus costs and you’ve seen that the cost side of the analysis is leading you nowhere, you can be certain that the declining profit is due to a decline in revenue.

Similarly, when you’re stuck on the quantitative section of the case interview, make sure that your framework for calculations is set up correctly (you can confirm this with the interviewer) and see what it is you’re trying to solve for: for example if you’re trying to find what price the client should sell their new t-shirt in order to break even on their investment, you should realize that what you’re trying to find is the break even point, so you can start by calculating either the costs or the revenues. You have all the data for the costs side and you know they’re trying to sell 10.000 pairs so you can simply set up the equation with x being the price.

As we’ve emphasised on several occasions, your case interview will be a dialogue. As such, if you don’t know what to do next or don’t understand something, make sure to ask the interviewer (and as a general rule always follow their prompts as they are trying to help, not trick you). This is especially true for the quantitative questions, where you should really understand what data you’re looking at before you jump into any calculations. Ideally you should ask your questions before you take time to formulate your approach but don’t be afraid to ask for further clarification if you really can’t make sense of what’s going on. It’s always good to walk your interviewer through your approach before you start doing the calculations and it’s no mistake to make sure that you both have the same understanding of the data. For example when confronted with the chart below, you might ask what GW (in this case gigawatt) means from the get-go and ask to confirm the different metrics (i.e. whether 1 GW = 1000 megawatts). You will never be penalised for asking a question like that.

5. Inside the Consultant’s Mind: Tools to Crack Consulting Cases

If you’re new to case cracking, it’s easy to feel overwhelmed when faced with a complex case question, unsure of where to begin.

Fortunately, like chess, the basic rules of solving cases are straightforward. Our problem-driven structure provides a clear, high-level framework to guide you. However, just like becoming a chess master, true proficiency in case interviews comes from understanding the nuances and building your skills through time and practice.

Beyond the approach, there are additional strategies and insights that consultants use, which can give you an edge. In this section, we’ll provide an overview of the core concepts you need to know, while linking to in-depth resources that will help you dive deeper into each topic.

5.1. An overall clear structure

Consultants thrive on structure, and this is one of the most important aspects to keep in mind during case interviews. Not only is it a key evaluation criterion, but it’s also the greatest tool at your disposal for tackling complex cases. Let’s break down the areas where a clear structure will make all the difference.

5.2. Common business knowledge and formulas

Although some consulting firms claim they don’t evaluate candidates based on their business knowledge, familiarity with basic business concepts and formulae is very useful in terms of understanding the case studies you are given in the first instance and drawing inspiration for structuring and brainstorming.

If you are coming from a business undergrad, an MBA or are an experienced hire, you might well have this covered already. For those coming from a different background, it may be useful to cover some.

Luckily, you don’t need a degree-level understanding of business to crack case interviews , and a lot of the information you will pick up by osmosis as you read through articles like this and go through cases.

However, some things you will just need to sit down and learn. We cover everything you need to know in some detail in our Case Academy Course course. However, some examples here of things you need to learn are:

• Basic accounting (particularly how to understand all the elements of a balance sheet)
• Basic economics
• Basic marketing
• Basic strategy

Below we include a few elementary concepts and formulae so you can hit the ground running in solving cases. We should note that you should not memorise these and indeed a good portion of them can be worked out logically, but you should have at least some idea of what to expect as this will make you faster and will free up much of your mental computing power. In what follows we’ll tackle concepts that you will encounter in the private business sector as well as some situations that come up in cases that feature clients from the NGO or governmental sector.

5.3 Public sector and NGO concepts

As we mentioned, there will be some cases (see section 6.6 for a more detailed example) where the key performance indicators (or KPIs in short) will not be connected to profit. The most common ones will involve the government of a country or an NGO, but they can be way more diverse and require more thought and application of first principles. We have laid out a couple of the key concepts or KPIs that come up below

5.4 Common consulting concepts

Consultants use basic logic business on an every day basis, as they help them articulate their frameworks to problems. However, they also use some consulting specific logical principles to quality check their analysis and perform in the most efficient way possible. These principles can be applied to all aspects of a consultant’s work, but for brevity we can say they mostly impact a consultant’s systematic approach and communication - two very important things that are also tested in case interviews. Therefore, it’s imperative that you not only get to know them, but learn how and when to use them as they are at the very core of good casing. They are MECE-ness, the Pareto Principle and the Pyramid principle and are explained briefly below - you should, however, go on to study them in-depth in their respective articles.

6. Building blocks

As we mentioned before, in your case interview preparation you will undoubtedly find preparation resources that claim that there are several standard types of cases and that there is a general framework that can be applied to each type of case. While there are indeed cases that are straightforward at least in appearance and seemingly invite the application of such frameworks, the reality is never that simple and cases often involve multiple or more complicated components that cannot be fitted into a simple framework.

At MCC we don’t want you to get into the habit of trying to identify which case type you’re dealing with and pull out a framework, but we do recognize that there are recurring elements in frameworks that are useful - such as the profitability of a venture (with its revenues and costs), the valuation of a business, estimating and segmenting a market and pricing a product.

We call these building blocks because they can be used to build case frameworks but are not a framework in and of themselves, and they can be shuffled around and rearranged in any way necessary to be tailored to our case. Hence, our approach is not to make you think in terms of case types but work from first principles and use these building blocks to build your own framework. Let’s take two case prompts to illustrate our point.

Bain Case Study Example

The first is from the Bain website, where the candidate is asked whether they think it’s a good idea for their friend to open a coffee shop in Cambridge UK (see the case here ). The answer framework provided here is a very straightforward profitability analysis framework, examining the potential revenues and potential costs of the venture:

While this is a good point to start for your case interview (especially taken together with the clarifying questions), we will notice that this approach will need more tailoring to the case - for example the quantity of coffee will be determined by the market for coffee drinkers in Cambridge, which we have to determine based on preference. We are in England so a lot of people will be drinking tea but we are in a university town so perhaps more people than average are drinking coffee as it provides a better boost when studying. All these are some much needed case-tailored hypotheses that we can make based on the initial approach.

Just by looking at this case we might be tempted to say that we can just take a profitability case and apply it without any issues. However, this generic framework is just a starting point and in reality we would need to tailor it much further in the way we had started to do in order to get to a satisfactory answer. For example, the framework for this specific case interview doesn’t cover aspects such as the customer’s expertise: does the friend have any knowledge of the coffee business, such as where to source coffee and how to prepare it? Also, we could argue there may be some legal factors to consider here, such as any approvals that they might need from the city council to run a coffee shop on site, or some specific trade licences that are not really covered in the basic profitability framework.

McKinsey Case Study Example

Let’s take a different case, however, from the McKinsey website. In this scenario, the candidate is being asked to identify some factors in order to choose where to focus the client’s conservation efforts. Immediately we can realise that this case doesn’t lend itself to any pre-packaged framework and we will need to come up with something from scratch - and take a look at McKinsey’s answer of the areas to focus on:

We notice immediately that this framework is 100% tailored to the case - of course there are elements which we encounter in other cases, such as costs and risks but again these are applied in an organic way. It’s pretty clear that while no standard framework would work in this case, the aforementioned concepts - costs and risks - and the way to approach them (a.k.a building blocks) are fundamentally similar throughout cases (with the obvious specificities of each case).

In what follows, we’ll give a brief description of each building block starting from the Bain example discussed previously, in order to give you a general idea of what they are and their adaptability, but you should make sure to follow the link to the in-depth articles to learn all their ins and outs.

6.1 Estimates and segmentation

This building block will come into play mostly when you’re thinking about the market for a certain product (but make sure to read the full article for more details). Let’s take our Bain Cambridge coffee example. As we mentioned under the quantity bucket we need to understand what the market size for coffee in Cambridge would be - so we can make an estimation based on segmentation.

The key to a good estimation is the ability to logically break down the problem into more manageable pieces. This will generally mean segmenting a wider population to find a particular target group. We can start off with the population of Cambridge - which we estimate at 100.000. In reality the population is closer to 150.000 but that doesn’t matter - the estimation has to be reasonable and not accurate, so unless the interviewer gives you a reason to reconsider you can follow your instinct. We can divide that into people who do and don’t drink coffee. Given our arguments before, we can conclude that 80% of those, so 80.000 drink coffee. Then we can further segment into those who drink regularly - let’s say every day - and those who drink occasionally - let’s say once a week. Based on the assumptions before about the student population needing coffee to function, and with Cambridge having a high student population, we can assume that 80% of those drinking coffee are regular drinkers, so that would be 64.000 regular drinkers and 16.000 occasional drinkers. We can then decide whom we want to target what our strategy needs to be:

This type of estimation and segmentation can be applied to any case specifics - hence why it is a building block.

6.2 Profitability

We had several looks at this building block so far (see an in-depth look here ) as it will show up in most case interivew scenarios, since profit is a key element in any company’s strategy. As we have seen, the starting point to this analysis is to consider both the costs and revenues of a company, and try to determine whether revenues need to be improved or whether costs need to be lowered. In the coffee example, the revenues are dictated by the average price per coffe x the number of coffees sold, whereas costs can be split into fixed and variable.

Some examples of fixed costs would be the rent for the stores and the cost of the personnel and utilities, while the most obvious variable costs would be the coffee beans used and the takeaway containers (when needed). We may further split revenues in this case into Main revenues - i.e. the sales of coffee - and Ancillary revenues, which can be divided into Sales of food products (sales of pastries, sandwiches etc., each with the same price x quantity schema) and Revenues from events - i.e renting out the coffee shop to events and catering for the events themselves. Bear in mind that revenues will be heavily influenced by the penetration rate, i.e. the share of the market which we can capture.

6.3 Pricing

Helping a company determine how much they should charge for their goods or services is another theme that comes up frequently in cases. While it may seem less complicated than the other building blocks, we assure you it’s not - you will have to understand and consider several factors, such as the costs a company is incurring, their general strategic positioning, availability, market trends as well as the customers’ willingness to pay (or WTP in short) - so make sure to check out our in-depth guide here.

In our example, we may determine that the cost per cup (coffee beans, staff, rent) is £1. We want to be student friendly so we should consider how much students would want to pay for a coffee as well as how much are competitors are charging. Based on those factors, it would be reasonable to charge on average £2 per cup of coffee. It’s true that our competitors are charging £3 but they are targeting mostly the adult market, whose willingness to pay is higher, so their pricing model takes that into account as well as the lower volume of customers in that demographic.

6.4. Valuation

A variant of the pricing building block, a valuation problem generally asks the candidate to determine how much a client should pay for a specific company (the target of an acquisition) as well as what other factors to consider. The two most important factors (but not the only ones - for a comprehensive review see our Valuation article) to consider are the net present value (in consulting interviews usually in perpetuity) and the synergies.

In short, the net present value of a company is how much profit it currently brings in, divided by how much that cash flow will depreciate in the future and can be represented with the equation below:

The synergies refer to what could be achieved should the companies operate as one, and can be divided into cost and revenue synergies.

Let’s expand our coffee example a bit to understand these. Imagine that our friend manages to open a chain of coffee shops in Cambridge and in the future considers acquiring a chain of take-out restaurants. The most straightforward example of revenue synergies would be cross-selling, in this case selling coffee in the restaurants as well as in the dedicated stores, and thus getting an immediate boost in market share by using the existing customers of the restaurant chain. A cost synergy would be merging the delivery services of the two businesses to deliver both food and coffee, thus avoiding redundancies and reducing costs associated with twice the number of drivers and vehicles.

6.5. Competitive interaction

This component of cases deals with situations where the market in which a company is operating changes and the company must decide what to do. These changes often have to do with a new player entering the market (again for more details make sure to dive into the Competitive Interaction article).

Let’s assume that our Cambridge coffee shop has now become a chain and has flagged up to other competitors that Cambridge is a blooming market for coffee. As such, Starbucks has decided to open a few stores in Cambridge themselves, to test this market. The question which might be posed to a candidate is what should our coffee chain do. One way (and a MECE one) to approach the problem is to decide between doing something and doing nothing. We might consider merging with another coffee chain and pooling our resources or playing to our strengths and repositioning ourselves as ‘your student-friendly, shop around the corner’. Just as easily we may just wait the situation out and see whether indeed Starbucks is cutting into our market share - after all, the advantages of our product and services might speak for themselves and Starbucks might end up tanking. Both of these are viable options if argued right and depending on the further specifics of the case.

6.6. Special cases

Most cases deal with private sectors, where the overarching objective entails profit in some form. However, as hinted before, there are cases which deal with other sectors where there are other KPIs in place. The former will usually contain one or several of these building blocks whereas the latter will very likely have neither. This latter category is arguably the one that will stretch your analytical and organisational skills to the limit, since there will be very little familiarity that you can fall back on (McKinsey famously employs such cases in their interview process).

So how do we tackle the structure for such cases? The short answer would be starting from first principles and using the problem driven structure outlined above, but let’s look at a quick example in the form of a McKinsey case:

The first question addressed to the candidate is the following:

This is in fact asking us to build a structure for the case. So what should we have in mind here? Most importantly, we should start with a structure that is MECE and we should remember to do that by considering all the stakeholders. They are on the one hand the government and affiliated institutions and on the other the population. We might then consider which issues might arise for each shareholder and what the benefits for them would be, as well as the risks. This approach is illustrated in the answer McKinsey provides as well:

More than anything, this type of case shows us how important it is to practise and build different types of structures, and think about MECE ways of segmenting the problem.

7. How Do I prepare for case interviews

In consulting fashion, the overall preparation can be structured into theoretical preparation and practical preparation, with each category then being subdivided into individual prep and prep with a partner.

As a general rule, the level and intensity of the preparation will differ based on your background - naturally if you have a business background (and have been part of a consulting club or something similar) your preparation will be less intensive than if you’re starting from scratch. The way we suggest you go about it is to start with theoretical preparation, which means learning about case interviews, business and basic consulting concepts (you can do this using free resources - such as the ones we provide - or if you want a more through preparation you can consider joining our Case Academy as well).

You can then move on to the practical preparation which should start with doing solo cases and focusing on areas of improvement, and then move on to preparation with a partner, which should be another candidate or - ideally - an ex-consultant.

Let’s go into more details with respect to each type of preparation.

7.1. Solo practice

The two most important areas of focus in sole preparation are:

• Full cases
• Mental math

As we mentioned briefly, the best use of your time is to focus on solving cases. You can start with cases listed on MBB sites since they are clearly stated and have worked solutions as well (e.g. Bain is a good place to start) and then move to more complex cases (our Case Library also offers a range of cases of different complexities). To build your confidence, start out on easier case questions, work through with the solutions, and don't worry about time. As you get better, you can move on to more difficult cases and try to get through them more quickly. You should practice around eight case studies on your own to build your confidence.

Another important area of practice is your mental mathematics as this skill will considerably increase your confidence and is neglected by many applicants - much to their immediate regret in the case interview. Find our mental math tool here or in our course, and practice at least ten minutes per day, from day one until the day before the interview.

7.2. Preparation with a partner

There are aspects of a case interview - such as asking clarifying questions - which you cannot do alone and this is why, after you feel comfortable, you should move on to practice with another person. There are two options here:

• Practicing with a peer
• Practicing with an ex-consultant

In theory they can be complementary - especially if you’re peer is also preparing for consulting interviews - and each have advantages and disadvantages. A peer is likely to practice with you for free for longer, however you may end up reinforcing some bad habits or unable to get actionable feedback. A consultant will be able to provide you the latter but having their help for the same number of hours as a peer will come at a higher cost. Let’s look at each option in more detail.

7.3. Practice for online interviews

Standard preparation for interview case studies will carry directly over to online cases.

However, if you want to do some more specific prep, you can work through cases solo to a timer and using a calculator and/or Excel (online cases generally allow calculators and second computers to help you, whilst these are banned in live case interviews).

Older PST-style questions also make great prep, but a particularly good simulation is the self-assessment tests included in our Case Academy course. These multiple choice business questions conducted with a strict time limit are great preparation for the current crop of online cases.

7.4. Fit interviews

As we’ve noted, even something billed as a case interview is very likely to contain a fit interview as a subset.

We have an article on fit interviews and also include a full set of lessons on how to answer fit questions properly as a subset of our comprehensive Case Academy course.

Here though, the important thing to convey is that you take preparing for fit questions every bit as seriously as you do case prep.

Since they sound the same as you might encounter when interviewing for other industries, the temptation is to regard these as “just normal interview questions”.

However, consulting firms take your answers to these questions a good deal more seriously than elsewhere.

This isn’t just for fluffy “corporate culture” reasons. The long hours and close teamwork, as well as the client-facing nature of management consulting, mean that your personality and ability to get on with others is going to be a big part of making you a tolerable and effective co-worker.

If you know you’ll have to spend 14+ hour working days with someone you hire and that your annual bonus depends on them not alienating clients, you better believe you’ll pay attention to their character in interview.

There are also hard-nosed financial reasons for the likes of McKinsey, Bain and BCG to drill down so hard on your answers.

In particular, top consultancies have huge issues with staff retention. The average management consultant only stays with these firms for around two years before they have moved on to a new industry.

In some cases, consultants bail out because they can’t keep up with the arduous consulting lifestyle of long hours and endless travel. In many instances, though, departing consultants are lured away by exit opportunities - such as the well trodden paths towards internal strategy roles, private equity or becoming a start-up founder.

Indeed, many individuals will intentionally use a two year stint in consulting as something like an MBA they are getting paid for - giving them accelerated exposure to the business world and letting them pivot into something new.

Consulting firms want to get a decent return on investment for training new recruits. Thus, they want hires who not only intend to stick with consulting longer-term, but also have a temperament that makes this feasible and an overall career trajectory where it just makes sense for them to stay put.

This should hammer home the point that, if you want to get an offer, you need to be fully prepared to answer fit questions - and to do so excellently - any time you have a case interview.

8. Interview day - what to expect, with tips

Of course, all this theory is well and good, but a lot of readers might be concerned about what exactly to expect in real life. It’s perfectly reasonable to want to get as clear a picture as possible here - we all want to know what we are going up against when we face a new challenge!

Indeed, it is important to think about your interview in more holistic terms, rather than just focusing on small aspects of analysis. Getting everything exactly correct is less important than the overall approach you take to reasoning and how you communicate - and candidates often lose sight of this fact.

In this section, then, we’ll run through the case interview experience from start to finish, directing you to resources with more details where appropriate. As a supplement to this, the following video from Bain is excellent. It portrays an abridged version of a case interview, but is very useful as a guide to what to expect - not just from Bain, but from McKinsey, BCG and any other high-level consulting firm.

8.1. Getting started

Though you might be shown through to the office by a staff member, usually your interviewer will come and collect you from a waiting area. Either way, when you first encounter them, you should greet your interviewer with a warm smile and a handshake (unless they do not offer their hand). Be confident without verging into arrogance. You will be asked to take a seat in the interviewer’s office, where the case interview can then begin.