Ernst & Young (EY-Parthenon) Case Interview: How to Prepare

Ernst & Young (EY) interviews consist of case interviews, group case interviews, and behavioral or fit interview questions. It is important to know that EY’s consulting business is divided into two different groups:

  • Strategy consulting (Parthenon Group)


  • EY Advisory


Strategy Consulting (Parthenon Group): EY acquired management consulting firm The Parthenon Group in 2014. Parthenon focuses on strategy and management consulting and does projects similar to the types of projects at McKinsey, BCG, and Bain. They focus on strategy, marketing, organization, operations, transformations, and mergers and acquisitions.


EY Advisory: This group focuses on customer experience, customer engagement, risk transformation, analytics, technology implementation, program management, and finance consulting services.


Depending on what group you are interviewing for, the types of case interview and group interview questions that you get can vary significantly.


For example, if you are interviewing specifically for EY’s strategy consulting group, formerly known as The Parthenon Group, your cases will be focused on business strategy and operations problems. If you are interviewing for EY Advisory, your cases would focus on technology implementation or risk transformation.


In this article, we’ll cover:

  • The interview process at EY-Parthenon


  • The 6 steps to solving any EY-Parthenon case interview


  • How to ace the EY-Parthenon group case interview


  • The 10 most common behavioral or fit interview questions


EY-Parthenon Interview Process


EY-Parthenon typically has two to three rounds of interviews.

  • First round: A 30-minute phone interview with a recruiter focused on behavioral or fit interview questions


  • Second round: Two 30-minute interviews conducted by Consultants or Managers. One interview is focused on behavioral or fit interview questions and the other is focused on a case interview.


  • Third round: Three 30 to 45-minute interviews conducted by Managers or Partners. One interview is focused on behavioral or fit interview questions, one is focused on a case interview, and one is focused on a group case interview


Depending on the office or group that you are interviewing for, you may not have an initial recruiter phone screen.


It is important to know that EY-Parthenon heavily emphasizes behavioral and fit interview questions in the final round of interviews. Interviewers want to ensure that candidates that are interviewing for EY-Parthenon actually want to work there and are not treating it as a backup firm.


In the following sections, we’ll cover exactly how to prepare and answer the three types of interview questions you may see in your upcoming EY-Parthenon interview:

  • Case interviews


  • Group case interviews


  • Behavioral or fit interview questions


6 Steps to Solve Any EY Case Interview or Case Study Interview


EY-Parthenon case interviews, also known as case study interviews, are all candidate-led. You will be in the driver’s seat of the case interview and will be expected to ask the right questions, probe for data, and propose each next step to solve the case.


Follow these six steps to solve any EY case interview or case study interview:


1. Understand the case


The case will begin with the interviewer giving you the case 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, the company, and the objective of the case.


2. Verify the objective


Understanding the business problem and objective of the case is the most important part of the case interview. Not addressing the right business question is the quickest way to fail a case interview.


Make sure that you ask clarifying questions to better understand the business situation and problem. Then, confirm that you understand the case objective with the interviewer. This ensures that you start the case on the right track.


3. Create a framework


Develop a framework to help you tackle the business problem. A framework is a tool that helps you structure and break down complex problems into smaller, more manageable components. With a framework, you’ll be brainstorming different ideas and organizing them into different categories.


Afterwards, walk the interviewer through your framework. They may ask a few questions or provide some feedback to you.


4. Develop a hypothesis


After creating a framework, you should develop a hypothesis. A hypothesis is an educated guess on the answer based on the data and information that you have so far.


Your hypothesis does not need to be correct. You’ll be continuously testing and refining your hypothesis throughout the case. The purpose of having a hypothesis is to guide your analysis and ensure that you are spending your time answering the right questions.


5. Test your hypothesis


The majority of the case will be spent testing your hypothesis.


After stating your hypothesis, it is up to you to lead the direction of the case. Depending on the context of the case, you may want to ask for data to do some analysis. You may also want to explore qualitative questions that you have. As you uncover more information, your hypothesis will likely have to change. 


Sometimes, your hypothesis will be completely wrong and you’ll need to develop a completely new hypothesis to test. Other times, your hypothesis may be on the right track, but you’ll need to refine or narrow it down further.


Throughout the rest of the case, you’ll be answering a mix of quantitative and qualitative questions. Make sure that after each question, you explain how your answer impacts your hypothesis or answer to the case.


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 summarizing only 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 yet or lingering questions that you do not have great answers for.


EY-Parthenon Group Case Interview


EY-Parthenon uses a group case interview in their final round of interviews. This special type of case interview assesses you on your collaboration and teamwork skills.


Here’s what you should expect:

  • You’ll be put into a group with 3 to 5 other candidates


  • The interviewer will hand out the case background materials


  • You’ll have one hour to review the materials, discuss with your group, and prepare presentation slides


  • During this discussion, interviewers will be observing candidates and will not interfere


  • The group will have 15 minutes to present their answers or recommendation


  • The interviewer will ask follow-up questions based on the presentation


Your goal in a group case interview is to add value to the group. There are six different ways that you can do this:

  • Lead or facilitate the discussion: You can propose what topics to discuss, the order they should be discussed in, and how much time should be allocated towards each topic. If the group gets off track, you can bring the group’s focus back together.


  • Expand upon other people’s ideas: If a group member suggests a great idea or raises a good point, build upon it and make it even better.


  • Synthesize information: You can summarize information that other people have said and reconcile different viewpoints and ideas together.


  • Keep track of time: You can volunteer to keep track of time and make sure that the group is on track.


  • Play devil’s advocate: You can help your group develop strong ideas by testing the team’s thinking by considering potential risks or downsides of their ideas.


  • Take notes: You can keep track of what other people are saying so that you can recall what has been discussed if any group members have questions.


Additionally, follow these five tips to improve your group case interview performance.


Tip #1: Treat your group members as teammates, not competition


The group case interview is not an exercise in which you are competing with others. Interviewers are trying to assess whether you would be a great teammate. Multiple people or even all people in your group can receive job offers.


Therefore, focus on adding value to the group rather than on making yourself look better than your teammates.


Tip #2: Don’t spend too much time reviewing the materials in silence


In the beginning of the group case interview, your group will likely want to spend time reviewing the case materials independently. This is fine to do, but make sure you move towards having a group discussion as early as possible.


There are likely many things that need to be discussed and decided on as a group, so reading materials in silence for too long is not a good use of time.


Tip #3: Don’t speak too much, but don’t speak too little


If you speak too much, this may be seen as being too aggressive or controlling. If you speak too little, you may come off as shy or timid.


If you were to rank all of the members in your group by how much each person spoke, you would want to be roughly in the middle. This would be the perfect balance between speaking and listening.


Tip #4: Don’t interrupt or talk over your group members


Interrupting others when they are speaking is rude and disrespectful. You do not want to be inconsiderate or a jerk. Be nice and respectful to your group members.


Tip #5: Involve other people


If you observe that someone has not spoken much, ask them for their thoughts or opinions. If you notice that someone has been cut off when they were speaking, ask them to finish their thoughts after the person interrupting them has finished what they have to say. This shows that you are a considerate and helpful teammate.


The 10 Most Common Behavioral or Fit Interview Questions


In addition to case interviews, you will likely be asked a few behavioral or fit interview questions. There are ten questions that are most commonly asked.


1. Why EY-Parthenon?


How to answer: Have at least three reasons why you’re interested in working at EY-Parthenon. You could mention that you loved the people that you have met from the company so far. You can talk about EY-Parthenon’s massive global presence and expertise in nearly any industry or function. You can speak to how EY-Parthenon provides strategy and implementation, so you can see the impact of your work.


2. Why consulting?


How to answer: Again, have three reasons why you’re interested in consulting. You could mention the fast career growth opportunity, the opportunity to develop soft and hard skills, or the level of impact that you can make by working with large companies on their most challenging issues.


3. Walk me through your resume


How to answer: Provide a concise summary of your work experience, starting with the most recent. Focus on emphasizing your most impressive and unique accomplishments. At the end, tie your experiences to why you are interested in consulting and why you would be a great fit for EY-Parthenon.


4. What accomplishment are you most proud of? 


How to answer: Choose your most impressive, unique, or memorable accomplishment. Structure your answer by providing information on the situation, the task, the actions you took, and the results of your work. Explain why the accomplishment is so meaningful to you and what qualities that reveals about you as a person.


5. Tell me about something that is not on your resume


How to answer: This is a great opportunity to highlight an accomplishment that is not related to your professional work experience. Perhaps there is a non-profit that you volunteer at, a side project or business that you work on, or a hobby that you have won awards or recognition for. Select an accomplishment that is impressive and interesting.


6. Tell me about a time when you had to lead a team.


How to answer: If possible, choose a time when you directly managed a person or a team. For this question and the following similar questions, make sure that you structure your answer. Provide information on the situation, the task, the actions you took, and the results of your work. This is known as the STAR method and is the most common way of answering behavioral or fit interview questions. 


7. Describe a time when you faced conflict or disagreement.


How to answer: When answering this question, focus on emphasizing the steps you took to resolve the conflict or disagreement. Speak about the interpersonal skills you had to use in order to mediate the situation. Interviewers want to know that you can handle conflict in a constructive way.


8. Give an example of a time when you successfully persuaded someone.


How to answer: Choose a time when you were able to change someone’s mind who originally disagreed with you. Focus on emphasizing the steps that you took to persuade that person and what impact this had on the organization. Interviewers want to know that you are a great communicator and have strong people skills.


9. Tell me about a time when you failed.


How to answer: Choose a time when you failed to meet a deadline or did not meet expectations. You do not want to pick a failure that is too big or embarrassing. Focus on emphasizing what you learned from the experience and how you used that experience to deliver even better results in the next opportunity that you got. Interviewers want to see that you strive to learn from your past failures and are always working to get better.


10. Are there any questions that you have for me?


How to answer: This is a fantastic opportunity to get to know the interviewer on a more personal level. Ask them questions about their experience in consulting. Ask what their favorite case was or what they are looking to do next in their career. The more you can get the interviewer talking about themself, the more likely they will be to have a positive impression of you.


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