EY-Parthenon Case Interview Guide (process & prep)

Ernst & Young (EY-Parthenon) case interview

Consulting interviews at EY and its strategy subsidiary Parthenon are tough. EY-Parthenon uses a combination of case interviews and behavioural interviews to evaluate candidates, with group case presentations also used sometimes.

This might sound overwhelming. But don't worry! We've helped thousands of applicants land consulting jobs, and this is our ultimate guide to EY-Parthenon interviews.

Learn all about the company, the interview process, EY case studies, which questions to expect and how to answer them. By following the information below, you'll be one step closer to getting an offer at EY. 

Here's an overview of what we'll cover:

  1. About EY-Parthenon
  2. Interview process
  3. Case interviews
  4. Interview questions
  5. Group presentations
  6. Preparation tips
Click here to practise 1-on-1 with consulting ex-interviewers

1. EY consulting is bigger than BCG and Bain

With $13.5bn in consulting revenue in 2022, EY's consulting business line is bigger than BCG and Bain, and on a par with McKinsey.

EY's broader consulting (or advisory) business can be divided into EY Advisory, and EY-Parthenon:

  • EY Advisory provides 3 primary services which are common at Big 4 firms.
    • Performance Improvement works across industries to help clients create streamlined processes and powerful systems. For example, helping an international firm like Nike reduce costs through strategic changes to their supply chain.
    • Performance Technology applies technology solutions to drive business performance. For example, using social media to help a firm like Disney market their vacation resorts to customers who are already interested.
    • Risk focuses on identifying, evaluating, and addressing risks faced by client businesses. For example, helping a financial institution like Morgan Stanley develop a response plan to prepare for a data breach.
  • EY-Parthenon focuses on strategy and management consulting. The type of work you'd do here is very similar to the work you'd find at McKinsey, BCG or Bain.

You can learn more about how EY compares to MBB firms in our MBB vs. Big 4 comparison article.

If you're interested in applying for a consulting role at EY then it's important to know what specific area you're interested in. 

This will help you be more focused in your application, and it will also show your level of preparedness to recruiters. It's not uncommon to be asked about specific areas of interest during interviews, and having a prepared answer using the company's own terms can really impress your interviewer.

For the rest of this post, we'll be focusing on the steps you'll need to take in order to land a job in EY-Parthenon. If you're applying for a role in EY Advisory, don't worry. There will likely be some differences, but 95% of the below guide is still relevant, and will provide an excellent overview of the consulting interview process.

2. EY-Parthenon interview process overview

The application process varies depending if you apply as an experienced hire or on a graduate or student recruitment program.

We'll start off by looking at experienced hires. Note that these steps outline the typical process, but the exact steps can vary based on location and role. Ask your HR contact if they can provide more details on the specific steps for your interview track.

2.1 Process for experienced hires

EY-Parthenon generally has 3 steps in their application process for experienced candidates:

  1. Resume and application screening
  2. First round interviews
  3. Second round interviews

Let's zoom in on each step.

2.1.1 Resume and application screening

First, recruiters will look at your resume/application and assess if your experience matches the open position. This is the most competitive step in the process—we’ve found that 90% of candidates don’t make it past this stage.

You can use this free resume guide and this free cover letter guide to help tailor your application to the position you’re targeting.

And if you’re looking for expert feedback, you can also get input from our team of ex-MBB recruiters, who will cover what achievements to focus on (or ignore), how to fine tune your bullet points, and more.

2.1.2 First-round interviews

After the initial application, you'll move onto the interviews. In the first round, you can expect:

  • Phone interview with someone in HR
  • One or two case interviews (45mins-1hr)

HR phone interviews will fous on your resume and your motivations for becoming an EY-Parthenon consultant. Then first-round case study interviews are usually with EY-Parthenon managers or consultants, usually via via video call.

2.1.3 Second-round interviews

Second-round interviews usually consist of:

  • One or two case interviews (45-60 mins)
  • A behavioural interview (45-60 mins)

Second-round case interviews are usually with senior members of the firm, such as directors, while the behavioural interview will most likely be with a partner. These interviews may be done in person at an EY office, or via video call.

As we said, the exact process varies across regions and roles, and some candidates have reported that each of their interviews had a mix of questions. So be prepared to be asked behavioural questions at the start of your case interviews.

In some cases, you may also need to do a written assignment or attend an assessment centre (see section 2.2.3 below).

Given the variation in the process, we strongly recommend that you ask your EY recruiter to confirm exactly what to expect.

We'll explain how to prepare for EY case interviews further down in section 3 and section 6.

2.2 Process for graduates, "Career Starters", etc

If you're still studying or recently graduated, your journey through the EY-Parthenon interview process will consist of four stages:

  1. Resume or application screening
  2. Online assessment
  3. EY Experience Day
  4. Final interview

Let's dive into each of those stages.

2.2.1 Resume or application screening 

In most cases you'll apply via the EY careers website. The HR team will assess your application and get back to you.

A large percentage of candidates don't make it past this stage, so make sure your consulting resume is top notch and consider booking a session with one of our coaches to help you with your application.

2.2.2 Online assessment

For "Career Starter" and similar positions, you'll need to take an online test, where you'll need to answer different types of questions, including ranking various options, giving writing answers and also giving video answers.

Depending on your position, you may be given a numerical reasoning test, too.

Do practice tests on the EY website.

2.2.3 EY Experience Day (with case study interview)

If you score highly enough in the online assessment, you'll be invited to an EY Experience Day. This is sometimes referred to as a "Super Day" or "Assessment Centre", but is now usually done virtually via Microsoft Teams.

Here you can expect to be put in a group with around 5 other candidates and given a group case study problem to solve. You'll get around 40 minutes to discuss the problem with your peers, before presenting together.

After that, you can expect to be given a written task to complete on your own.

Below in section 4 we'll cover how to ace your group case presentation.

2.2.4 Final interview with a partner

If you get through the EYX (EY Experience Day) you'll face an interview with a EY partner.

This will consist of behavioural and motivation questions, as they'll be wanting to make sure you're the right fit for EY and are highly motivated for the role.

"The partner interview is the final stage in our process and is very much about getting to know you as a person. We want to know why you have applied to this specific office and specific service line & what your career motivations are. We also ask you questions to test your commercial awareness of our industry & that you know about the firm and our competitors. Finally due to the new virtual nature of our assessment days we will also be asking about your teamwork and collaboration during the final interview." Clare H, Talent Attraction Advisor at EY.

Now that you have a good overview of the EY-Parthenon interview process, let's go deeper into the kind of questions to expect and how to approach them.

3. EY-Parthenon case interviews

Case interviews at EY-Parthenon are candidate-led. The style is similar to what you will experience in a BCG or a Bain case interview. This is different to firms like McKinsey or Capital One who use interviewer-led cases.

For a candidate-led case interview, there are 7 types of questions you need to prepare for:

  • Situation
  • Framework development
  • Framework exploration
  • Quant question – Data provided
  • Quant question – No data provided
  • Creativity question
  • Recommendation

EY-Parthenon case interviews often include a quant question where too much data is provided (a "data dump") and part of the challenge is for you to evaluate which information is useful and what isn't'. (source: Reddit).

You can read more about case interviews and how to prepare in our free case interview guide.

Candidates can also expect market sizing questions, such "estimate how many tacos are sold in Boston each year". To prepare, see our market sizing questions guide.

If you want to get a sense of what candidate-led case interviews are like, watch the video below. As we mentioned, case interviews at EY-Parthenon are typically candidate-led and therefore use the same format as BCG and Bain.



4. EY-Parthenon behavioural interview questions

At EY-Parthenon, there are two main categories of behavioural interview questions:

  1. Fit questions. These are generic questions such as “Why consulting?” or “Why EY?”.
  2. Personal Experience Interview (PEI) questions. These are questions such as “Tell me about a time when you led a team through a difficult situation.” Or “Tell me about a time where you had to manage a team conflict”

Here are the top 5 fit and PEI questions you should prepare for at EY-Parthenon or other top consulting firms.

Top 5 fit questions:

Top 5 PEI questions. Tell me about a time when ...

  • You led a team through a difficult situation
  • You worked in a team and had to manage a conflict
  • You had a disagreement with a colleague / boss
  • You had to change someone's / a group's mind
  • You overcame a really difficult challenge

Don't fall into the trap of under-preparing for these types of questions. While they may seem easier than the case interviews, they are extremely important to get right.

You’ll need to prepare several ”stories” or “examples” from your personal and professional experience to demonstrate that you have the traits that EY is looking for.

To learn more, check out our guide to consulting fit / PEI questions.

5. EY-Parthenon group case presentation

As mentioned in the overview above, EY-Parthenon frequently uses group case presentations in the interview process. Here is the key information you need to be aware of for this type of interview:

  • Candidates get divided into groups of 3 to 5
  • Each group is given information about a case (i.e. a client facing a problem)
  • You are given ~45 mins to review and prepare a 15 minute group presentation
  • An interviewer will watch during your prep time, but they won't intervene
  • After your group presents, the interviewers will ask questions for 15-20 minutes

This interview format is fairly unique, but it is similar to a written case interview, so you may find our free guide on written case interviews helpful. When you perform group exercises, your interviewers will be focusing on your ability to work well with others. And there are a handful of things you should make sure you do (and don't do).

Here are the top 4 things you should aim to do:

  • Speak with a purpose. This applies to the preparation and presentation. A lot of candidates will want to speak their minds as they know participating is important. But, participation alone is not enough. The QUALITY of your input is crucial. Sometimes, it's better to let two or three people speak first, and then make a very thoughtful point based on how they started the discussion. Focus more on the quality of your input, and less on the quantity.
  • Involve everyone. During preparation, keep an eye on who's participating in the conversation and who's not. If you identify a member of the group who's struggling to make themselves heard, you should not hesitate to help them by saying something like: "We haven't heard everyone's opinion on this yet. John, Rebecca what do you think?". This is a sign of leadership, and will also help you develop a more thoughtful and balanced presentation. 
  • Summarise. Plan to summarise key points during both preparation and the presentation. This will position you as the person bringing everyone together and making sure all candidates are on the same page. Aim to do this at least once during your prep time. For example, summarise the assignments of each group-member, or recap the group's key points at the end of the 1-hour prep time. This is a skill used by partners in real-world conversations with clients. You can also do this when presenting, by clearly recapping your main points.
  • Anticipate questions. During your preparation, you may notice some weaknesses in your analysis. It's good to carve out 5 minutes, to think through how you would answer challenges from the interviewers. It can also be helpful to ask yourself questions, like "if I was hearing this for the first time, what would I ask about?". The interviewers won't always ask the questions you most expect, but if they do, you'll be prepared with a thoughtful response.

And the top 4 things you should really avoid doing:

  • Looking nervous. A group interview is a good time to use your poker face. Everyone is stressed, but you need to come across as confident. A good way to do this is to focus on basic body language: look at people in the eye, sit confidently, don't cross your arms, etc.
  • Interrupting others. Consultants need to be client-friendly, and interrupting someone in a discussion is not client-friendly at all. You should listen carefully to what others are saying. Try to have a genuine interest in what they think. Before making your point, summarise their point to show that you understand what they mean.
  • Spending too much time reading. It's important to understand the case materials, but if you're not careful it could consume your full preparation time. A great way to prepare efficiently, is to first scan through the provided materials (just a couple minutes), and to agree upon one or two initial hypotheses. This allows you to then search for specific data points, that confirm or disprove it, before you finalise your approach. 
  • Dominating speaking time. Some candidates are so eager to participate that they end up completely dominating the rest of the group without realising it. Avoid doing this during the 1 hour prep time, and during the presentation itself. Recruiters will be paying close attention to both situations. A practical way of doing this, is to keep an eye on how much time you talk. If you are in a 5-person group you should aim to speak 20% (1/5th) of the time and really no more than 25%. 

Your performance in individual interviews and the group case presentation will play a big role in the firm's decision to give you an offer. If you'd like to learn more about how to prepare, check out our separate in-depth guide to group case interviews.

6. EY-Parthenon case interview preparation plan

Now that you know what to expect in EY-Parthenon interviews, let's discuss the steps you should take to prepare.

6.1 Learn the case interview essentials

The best starting point for your case interview prep is our case interview prep guide. It'll take you through all the different types of questions you may be asked in your case interview, show you how to draw from different frameworks to structure your answer, and give you example cases to practise with.

For further practice, EY Port Jackson Partners, a boutique consulting firm bought by EY in 2020, shares some nice EY case study interview examples on its website. Practise outlining your approach before clicking "show answer" to see their suggestions.

6.2 Become really confident at maths

You don't have to have a perfect GPA or GMAT score to succeed at case interview maths. However, during your EY-Parthenon interviews, you will be expected to quickly perform accurate mental maths.

In order to do this, it’s essential to know the formulas for common metrics, like return on investment or breakeven point. And it’s also helpful to know a few maths shortcuts to help you solve problems more quickly. To learn more about these topics, check out our free guide to case interview maths

In our experience, the most successful applicants start their interview preparation by practising maths skills, so make sure you prioritise this step.

6.3 Research the company

EY interviewers want to hire candidates who are deeply motivated to work for their firm. And while the firm no longer explicitly talks about wanting a team that is "smart, nice, driven", that was the mantra for many years and still is a fairly accurate summary of what it's looking for.

So make sure to read up on EY-Parthenon values and culture and present yourself accordingly.

Also, you'll want to make sure you're up to date in the latest developments in the area of the company you're applying to join. Here are some useful links to help you continue your research:

In addition, do some networking so that you can show you've made the effort to reach out to current staff.

6.4 Do mock interviews

How you solve each case is important, but your interviewers will also be evaluating how you COMMUNICATE your answers. It's important to speak in a structured way that makes it easy to clearly understand your points.

The best way to hone your communication skills is to practise interviewing out loud, and you can do that in three main ways:

  1. Interview yourself (out loud)
  2. Practise interviewing with friends or family
  3. Practise interviewing with ex-interviewers

To help you with this process, here is a broad list of consulting interview questions you can practise with. Practising by yourself is a great way to get started, and can help you get more comfortable with the flow of a case interview. However, this type of practice won’t prepare you for realistic interview conditions.

After getting some practice on your own, you should find someone who can do a mock interview with you, like a friend or family member.

We’d also recommend that you practise 1-1 with ex-interviewers from EY-Parthenon. This is the best way to replicate the conditions of a real case interview, and to get feedback from someone who understands the process extremely well. Meet our MBB ex-interviewers who’d love to work with you.