Ernst & Young (EY-Parthenon) case interview: the only post you'll need to read

Compared to a typical corporate interview, interviewing at EY and their strategy subsidiary Parthenon is very difficult. EY-Parthenon uses a combination of case interviews, behavioural interviews, and group case presentations to evaluate candidates.

If you're new to the case interview process, then this might sound overwhelming. But don't worry! We've helped over 30,000 consulting applicants, and this post is our ultimate guide for EY-Parthenon interviews.

Below you'll find helpful background on EY, the steps in their interview process, and key skills for succeeding. 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. Presentation
  6. Preparation tips
1. EY consulting is bigger than BCG and Bain

If EY's consulting business was spun-off, it would rival the size of MBB firms. With $9.6bn in consulting revenue in 2018, EY's consulting business line is bigger than BCG ($6bn),  Bain ($4bn), and nearly as large as McKinsey ($10bn). 

Over the last few years, consulting services have proven to be an important growth driver for EY and other members of the Big 4. This growth has been fueled through acquisitions, notably EY's acquisition of Parthenon Group in 2014. 

Parthenon was originally founded by former executives from Bain & Company in 1991. The firm grew to model the prestige of MBB firms, but with it's own unique culture (see "smart, nice, driven" below). Fast forward to the 2014 acquisition, which formed the new entity called EY-Parthenon, an EY subsidiary focused on strategy consulting.

To simplify things, 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

      EY-Parthenon has 3 steps in their application process.

      1. Resume and cover letter screening
      2. First round interviews
      3. Second round interviews

      These steps outline the typical process. However, for consulting jobs the steps for interviews can vary based on location and role. It can be really helpful to ask your HR contact if they can provide more details on the specific steps for your interview track.

      First, recruiters will look at your resume 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.

      After the initial application, you'll move onto the interviews. In the first round, you'll typically face a single interview, which is 1/2 case interview, and 1/2 behavioural interview. This is sometimes done in person, and sometimes done over the phone.

      During the behavioural interview portion, they may throw-in a market sizing question, for example: "how many tacos are sold per day in Boston?". Read more about them and learn an answer framework in our market sizing guide. For a long list of market sizing questions with high quality answers, see here.

      Second round interviews are usually a "Super Day". Note that the term "Super Day" is usually used in the US, and the term "Assessment Centre" is more common in Europe. This is basically just an on-site office visit, where you perform a series of interviews.

      Super Day (Assessment Centre) overview:

      1. Case interview
      2. Behavioural / fit interview
      3. Group case presentation

      You'll probably just have one of each of these interviews during the second round, but the company values adaptability, so be ready to roll with anything unexpected.

      In the following sections, we'll provide more details on the recruitment steps for EY-Parthenon, including tips and resources for how to prepare.

      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

      You can read more about case interviews and how to prepare in our free case interview guide. You can also get a sense of what candidate-led case interviews are like, using 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. Top behavioural interview questions asked at EY-Parthenon

      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 lead a team through a difficult situation.” Or “Tell me about a time where you had to manage a team conflict”

        We've written extensively about consulting fit / PEI questions in the past. But in summary 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:

        • Why EY?
        • Why consulting?
        • Walk me through your resume
        • Tell me about something not on your resume
        • Tell me about your greatest accomplishment

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

        • You lead 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

        If you would like guidance on how to answer PEI questions, you can check our article on the topic here.

        5. EY-Parthenon group case presentation

        As mentioned in the overview above, EY-Parthenon also uses a group case presentation to evaluate candidates during the second round. 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 1 hour 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 mind 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:

        • Being easy to read. 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 group case interviews, check out our separate in-depth guide here.

        6. EY-Parthenon case interview preparation plan

        So what's the best way to prepare for your EY-Parthenon interviews?

        Let's step go through some of the most important things you need to do to make sure you're fully prepared.

        6.1 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.  

        6.2 Develop a consistent method to crack cases

        One of the biggest challenges of interviewing with EY-Parthenon is solving cases that you’ve never seen before. Each case can be difficult, and you’ll have to perform well across multiple case interviews in order to get an offer.

        As a result, it’s critical for you to have a consistent approach for solving cases. EY-Parthenon uses candidate-led case interviews, which can be broken down into the following types of questions:

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

        If you can crack each type of question (within a case), then you can crack the overall case. To learn how to use this process to solve EY-Parthenon cases, you can use our BCG & Bain Case Interview Training Programme. EY-Parthenon uses the same type of case interviews as BCG and Bain, so you can use that programme to prepare. 

        6.3 Practise cases out loud

        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 peers
        3. Practise interviewing with ex-interviewers

        To help you with this process, here is a broad list of consulting interview questions you can practice 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. You can ask a friend or family member to help you, or you can apply to our free mock interview platform to find other consulting candidates to practise with. 

        We’d also recommend that you practise with ex-interviewers from EY-Parthenon. This is the best way to replicate the conditions of a real interview, and to get feedback from someone who understands the process extremely well. You may not have the connections to do this on your own, but we’ve made the connections for you. Meet our EY-Parthenon ex-interviewers who’d love to work with you.

        6.4 Learn from every mistake you make

        During case interview preparation, the quality of your preparation is just as important as the quantity of time that you dedicate. It's better to do 20 cases thoughtfully than to rush through 40 cases. 

        We recommend that you keep a notebook where you record improvement opportunities and specific things you did well for each case. 

        The notebook and self-evaluation will help you to be more strategic (and efficient) with your preparation. It's also a good idea to go back and re-do old cases. For example, after you have done case #20, you could go back to case #1, to make sure you are not repeating the same mistakes.

        The minimum preparation time required to succeed in case interviews is probably around 30 hours. However, if you don't prepare thoughtfully, it may take much longer. So take notes, be strategic, and keep practicing!

        6.5 Show you are 'smart, nice, driven'

        When EY-Parthenon is looking to hire, they have a motto they use to identify the ideal candidate. This motto is "smart, nice, driven".

        You can guess the overarching idea. People within EY-Parthenon are proud of the company's culture, and want their new hires to mesh with this description. From an outside perspective, I think there are two things worth learning from this.

        First, whereas all consultancies place value on being smart and driven, Parthenon elevates the way their people treat others. Here's why this is interesting. If you're drawn to the challenge of a consulting career, but also want some of the relational benefits of a small-firm culture, then EY-Parthenon might be a great fit for you.

        Second, during the interview process, you are likely to encounter this motto. Just by knowing this in advance, you can take steps that will really set you apart from other candidates. Targeting your cover letter to highlight situations in which you embodied these qualities is a great start. You can also be strategic about including these ideas in your interview answers and conversations with recruiters.

        6.6 Don't waste your time

        You could spend hours bouncing around the internet, trying to decide on what process to use to solve case interviews. And the more time you spend sorting through different opinions and fragmented resources, the less time you’ll spend focused on REAL preparation. 

        Instead, we recommend that you focus on learning a single systematic approach to solving case interviews. 

        If you’d like to fast-track your preparation and maximise your chances of getting an offer at EY-Parthenon, come and train with us. More than 80% of the candidates training with our case interview programmes end up getting an offer at their target firm. We know this because we give half of their money back to people who don't.

        You can find a link to our BCG & Bain Case Interview Training Programme below. As mentioned previously, EY uses the same type of case interviews as BCG and Bain. So you can therefore use that programme to prepare for EY.

        BCG & Bain Case Interview Training Programme

        BCG & Bain case interview training programme

        Any questions about EY-Parthenon case interviews?

        If you have any questions about case interviews, do not hesitate to ask them below and we will be more than happy to answer them. All questions are good questions, so go ahead!

        The IGotAnOffer team