ZS Associates Case Interview 2024: Format, Samples & Guide

The ZS Associates case interview takes place in the last round of the company’s recruitment procedure. It is the most important component to decide whether a candidate is hired by ZS Associates. 

In this article, we will discover the details of the ZS Associates case interview, from its format to question types and tips to pass. 

What is ZS case interview?

ZS case interview is the last test to become an ZS consultant

The ZS case interview is the screening interview of ZS Associates, where candidates must solve business problems (or cases). The interview evaluates whether candidates possess the capabilities and qualities to become a ZS consultant.

ZS case interviews are candidate-led, requiring the candidate to lead and manage every step of the case-solving process, including structuring the issue, developing frameworks, requesting data, synthesizing findings, and providing solutions. The interviewer just presents the topic, instead of asking questions concerning the case.

Before getting to the case interview, you must pass the initial screening rounds, which include resume screening and aptitude test.

In the resume round, you’ll of course need a consulting resume, just like what you’d need for McKinsey, and a cover letter, then submit it on ZS’s website.

The aptitude test concerns numerical, verbal, and logical reasoning questions. It’s quite similar to McKinsey’s problem solving test before it was retired and replaced by the problem solving game.

These tests should take around 90 minutes. After taking the tests, you’ll join a video-based screening interview.

ZS cases are split into a written case and an oral case

The written case comes first, then after finishing it, you move on to the oral case.

In the written case, you will be provided with 5 to 6 graphs and charts depicting a business scenario and 4 to 8 questions based on the charts. This case is often 10 to 15 pages long and has a time limit of 30 to 45 minutes.

If you can’t answer all of the questions in the case, you should at least go through them and establish a logical approach to the case. It would be helpful in the next part. 

After the written case study, you will have a discussion with a recruiter about one or more business-related cases for around 30 minutes.

You need to present your approach to the case by asking relevant questions and finding out the root causes of the problems as well as the solutions. So, quite typical of consulting case interviews.

You may also be asked to discuss the written case study. This is the chance for you to present how you plan to approach and solve the incomplete questions (if any).

As with any case interview, how you approach the problem is more important than how accurate or complete your answers are. As long as you have a logical rationale for your approach, you can still pass the interview even if you haven’t answered every question in the case. 

ZS looks for those with achieving & analytical mindset

Just like all management consulting firms, ZS looks for those who want to make an impact. The main value ZS will look for are:

  • Outstanding academic achievement: Your GPA and school prestige. Your best bet? 4.0 at Harvard! But jokes aside, a 3.6 GPA should be good. Below that? Try to make focus points in other parts of your resume. This article might help!

  • Analytical ability: The ability to create a thorough, data-driven, insightful analysis and define the root cause and solutions to difficult problems. You show this in the case interview via constructing issue trees, answer guesstimate questions, etc.

  • Demonstrated leadership: The ability to inspire and motivate others. Consultants won’t simply look for “leaders” who just tell their subordinates what to do, but a guiding beacon, even for their superiors (very much like telling your boss what to do, but, think of it as inspiring ideas to them).

  • Collaborative approach: The ability to exchange facts and insights and effectively interact with people from various backgrounds and cultures. You’ll meet people hailing from mathematics, engineering, accounting, psychology, so play your collab cards right

  • Intellectual curiosity: The ability to actively and continuously seek and expand knowledge. To do this, start reading sơm business papers, and make sure you can absorb them 


ZS case interview questions

ZS focuses on 3 types of questions: chart insight, framework/issue true, and market sizing & guesstimate questions.

Chart questions are the core of the written case

The written case will present you with 5-6 charts and graphs, and your job is to answer some questions based on the charts. Bar charts, line graphs, pie charts, and scatter plots are the most common occurrences.

Here’s a bar chart question you might face:

Issue tree questions are staples of case interviews (of course)

Framework/issue tree questions are commonly used in ZS Associates’ oral case interviews, well, just like in any case interview from any consulting firm. For these questions, candidates are often asked to find the causes and solutions for a business problem.

Here’s a very simple issue tree, so you can get the idea:

You can also check out this dedicated article on issue tree to know more! It’s so popular in consulting that I believe this should be the first thing to understand when starting with case interviews.

Market-sizing & guesstimate questions are also present in oral cases

Another case interview staple! Of course ZS will test your ability to quantify something using logic and analytics. And remember, what your answer is isn’t important, but how you get to that answer. 

Here’s some example of market sizing questions:

  • How many mobile phones are sold in the USA in 2022?

  • If you open a plant shop, how much money can your monthly profit be?

  • What is the size of the watch market in Portugal?

Guesstimate questions are similar, just lacking the business stuff, like:

  • How many steps does one take to walk across Los Angeles?

  • How much air is needed to fill a hundred balloons?

  • How many cyclists are living in New York City at the moment?

These questions will test your ability in mental math, logical thinking, problem-solving, and background knowledge. When dealing with these questions, you should set up a work frame including structural steps and related questions.

It could be complicated at first, but anyone can answer market-sizing & guesstimate questions after practicing with the right approaches. To know more about those techniques, here’s a dedicated article on market-sizing & guesstimate questions!

And don’t forget the fit interview

Some may say fit interviews don’t matter, but I believe they set the tone for the later interviews, so you’d better make a damn good first impression. ZS will ask you some behavioral and typical HR questions, and everything should take some 30 minutes.

ZS actually lists some important questions on the website so you can prepare prior to the interview. Let’s check some of them out.

Q1: Tell us details about your challenges, goals, and the actions you’ve taken to meet the moment

These questions are competency-based. Using the STAR approach should be your best bet (framework, guys). Here’s how you go:

  • Situation: Start with the settings of your challenge

  • Task: Then move to what you needed to do to overcome the challenge

  • Action: Demonstrate specifically the steps you took to solve the problems. Be clear about the rationales behind your actions.

  • Result: Conclude with the outcomes of your efforts to show how result-driven and competent you are

Q2: Demonstrate that you are curious and a constant learner who can take on a variety of challenges

For this one, talk about some of your learning experiences. Maybe, when you took charge of a role you’d never been in before, or when you tried to pursue a challenging interest. The important thing is, show your eagerness to learn.

Q3: Show your capacity to leverage analytics and technology to bring innovative solutions to complex problems

ZS is quite a tech-savvy firm, so you should show how tech-savvy you are. Prepare yourself with both knowledge and experience in tech and business. If you haven’t had any practical experience, focus on your technical skills.

And I tell you what, if you don’t know where to start, start with ChatGPT. It’s AI at your disposal. Use it in some tasks like writing reports, train it to get better at those tasks. It may be small, but it’s a whole new world. 

Besides, it’s free. Why wait?

Q4: Talk about your experiences working with others and collaborating with teams, especially under challenging circumstances

Approach these questions the same way you do with the first types but concentrate on your teamwork. Emphasize your contributions to group work experiences and how the final results reflect your efforts. 


How to prepare for ZS case interview

Careful preparation is a must to ace ZS’ case. You can tackle each aspect of the interview step by step.

Start from getting used to candidate-led cases, then further out with business intuition, consulting math, fundamentals & frameworks of case interview, then finally conduct mock interviews.

Step 1: Get used to the candidate-led case interview, and written case interview

Examine examples of candidate-led case interviews to familiarize yourself with the case flow and how to interact with the interviewer.

You can also get familiar with more case interview samples and all instantly-effective tricks for case interviews with our Case Interview E2E Secret Program. Also, here’s our free video of a case interview example with an explanation and expert comments.

Step 2: Develop business intuition

Having business intuition significantly improves your performance in case interviews. Working on intuition is a gradual process that takes practice every day. You can improve your business intuition in two ways:

  • Written sources: Read business papers daily (Bloomberg is recommended). You can also find articles on McKinsey, Bain, and BCG’s websites. But be careful! The important thing is not your page count, but what you absorbed from them

  • First-hand experience and observations: Don't just do things like a machine; find out what the seniors are doing, why they did what they did, and how it has affected the organization. Everything is a learning process, and it’s up to you to squeeze out every bit of knowledge and experience

Step 3: Practice consulting math

Mental math is as consulting as MECE. Consultants work with quantitative data in just about every minute.

It is just takes too long to whip out a calculator every time they need to calculate something, and you’re definitely not impressing clients with that. That’s why interviewers place such high emphasis on mental math skills of interviewees. 

To improve your math, you can:

  • Train your head: Apply mental calculations on any daily occasion unless an EXACT answer is required

  • Start small: Use a piece of scratch paper, give yourself some margins of error (5% is a good start); once you get used to it, remove the paper and narrow down the margin of error.

  • Establish a routine: Spare time for daily practice and get better each day, just like exercise. You’ll never notice the little changes, but they stack up HARD, and when you realize it, you’re probably doing math thrice as fast

Step 4: Learn to read graphs & charts

The written case is charts galore, so you should at least grasp the purposes of each chart and develop your own approach to them.

Start easy, from bar, pie charts, then moving one to more advanced stuff like mixed charts or scatter plots (I myself would also suggest candlestick charts), you’ll get the hang of it in no time.

Step 5: Learn the fundamentals and frameworks of case interview

ZS case interviews (or any other case interview) are based on the fundamentals - using hypotheses and issue trees, the MECE principle, and the frameworks. So, knowing them is extremely important and you should practice the fundamentals until you are comfortable.

A common mistake candidates make during their case interviews is to go straight for the frameworks. Frameworks require extensive adaptation to match actual cases. To customize appropriately, you must understand the fundamental knowledge first.

To know more about case interviews, here’s a dedicated article.

Step 6: Conduct mock case interview

Mock interviews are a great way to simulate the actual case interview session. You should examine your cases in great depth during the mock case interview. Record your session, replay, note the comments, and look for ways to improve.

Find a former consultant to help you with your practice - they are the ideal people; they've been there, they’ll know what a candidate must be. Through their feedback, you can improve on what needs to be improved and boost your chance of getting an offer.

Techniques to approach problems in ZS Associates case interviews can be hard to master at first tries, hence the importance of practice. To be a competitive candidate for the company, you should spend time training with quality study materials. For a complete guide, covering everything you need, check out our Case Interview Program!

We can also help you connect with consulting coaches (all former consultants!) for a more personalized feedback. Book your mock case interview session with us now!

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