Deloitte case interview prep: the only post you'll need to read

Deloitte interviews are pretty challenging compared to regular interviews at large corporates. The questions are difficult and the interview format is specific to Deloitte.

But the good news is that with the right preparation it can actually become relatively straightforward to succeed at a Deloitte interview. We have put together the ultimate list of facts and tips you need to know to maximize your chances of success.

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

  1. Introduction
  2. Interview process
  3. Regular case interviews
  4. Group case interviews
  5. Fit and PEI questions
  6. Preparation plan
1. Deloitte Consulting is bigger than McKinsey + BCG

Deloitte is a force to reckon with in consulting. In 2017, it generated ~$14bn in revenue from its consulting business line. This makes it about as big as McKinsey (~$10bn) and BCG (~$5bn) combined.

Deloitte Consulting grew through a series of acquisitions. As a result, it's a collection of relatively independent firms operating under the Deloitte Consulting umbrella. Each member firm is managed by local partners who are responsible for their P&L. The different geographies are therefore less integrated than at a firm like McKinsey which mainly grew organically.

Deloitte Consulting has three main practice groups you need to be aware of when applying:

1. Strategy and Operations (S&O) focuses on topics such as corporate strategy, supply-chain improvement, business model transformation, process improvements, etc.

2. Technology consulting focuses on digital strategy, delivery of IT programmes, cyber risks management, designing and building tech-based solutions for clients, etc.

3. Human capital focuses on topics such as organisation transformation, change management, corporate learning and development, diversity and inclusion, etc.

The type of work Deloitte S&O does is very similar to what you would do at McKinsey, BCG and Bain. In 2013, Deloitte acquired Monitor which was initially founded by Michael Porter, the father of Porter's five forces. Monitor is now part of Deloitte S&O and that brand is particularly strong in North America.

2. Deloitte interview process

Deloitte uses 3 steps in its recruiting process:

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

The exact format of each interview round will vary slightly by country. Below we step through the format that's currently being used in the US. If you are applying in another country you can still use this as a rough guide of what to expect. In addition, we recommend that you ask your local HR contact at Deloitte for more details.

First round interviews usually contain one behavioural interview (30 to 45mins) and one or two case interviews (30 to 45mins each). This is quite similar to what you could expect at other consulting firms.

Second round interviews are slightly different however. They include one case interview and one behavioural interview, like in the first round. But in addition, you will also be asked to complete a group case interview.

Let's step through regular case interviews and group case interviews at Deloitte in more details. You can also look at a few case interview examples on Deloitte's website.

3. Deloitte uses similar cases to BCG and Bain (candidate-led)

Case interviews at Deloitte are candidate-led. The style is therefore similar to what you will experience in a BCG case interview or a Bain case interview. As we have mentioned in the past there 7 types of questions you need to prepare for in candidate-led case interviews:

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

You can learn more about case interviews and how to prepare in our free case interview guide. One unique thing about Deloitte case interviews is that they will occasionally (but not always) give candidates written materials and a few minutes to review before they start the interview. This type of scenario requires the kind of skills you could learn in our free written case interview guide. You can also see an example of written case materials in this practice case published by Deloitte.

To get a sense of what case interviews at Deloitte are like, you should have a look at the video below. As we mentioned, case interviews at Deloitte are candidate-led and therefore use the same format as BCG and Bain case interviews.

4. The second round also includes a group case interview

As mentioned above, Deloitte also uses group case interviews in its final round. Here is the key information you need to be aware of for this interview format:

  • Candidates get divided into groups of 4 to 6
  • Each group is given information about a case (i.e. a client facing a problem)
  • You are given 10mins to review the materials by yourself or with another person in your group
  • You are then asked to discuss a few questions about the case for 20mins with the rest of your group in front of your interviewers
  • The interviewers will ask a few questions to the group for 15 to 20mins

This type of case mainly tests your ability to work with others. Interviewers won't intervene during the group discussion. They will just observe the group dynamics and mark each participant based on how they are contributing to the discussion.

Here are the top 3 things you should aim to do in your Deloitte group interview:

  • Speak with a purpose. At the beginning of a group discussion, a lot of candidates will want to speak their mind as they know participating is important. But participating is not enough. The QUALITY of your input is crucial. Sometimes, it's better to let two or three people get the discussion started. And to then make a very thoughtful point based on how they started the discussion. Focus on the quality of your input, not the quantity.
  • Involve everyone. Another tip that's easy to apply is to 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 be heard by saying something like: "We haven't heard everyone's opinion on this yet. John, Rebecca what do you think?"
  • Summarise. Finally, at the end of the 20 minutes group discussion it's a good idea to summarise the different points people have made. This will position you as the person bringing everyone together and making sure all candidates are on the same page. It is something some partners in consulting like doing with clients in real life and will therefore reflect positively on you.

And the top 3 things you should really avoid doing:

  • Being easy to read. Group interviews is the time to put your poker face on. Everyone is stressed in a group interview. But you need to try your best to come accross 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.
  • Dominating the conversation. Finally, some candidates are so eager to participate in the conversation that they end up completely dominating the rest of the group without realising it. A good tip to avoid 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 regular and group case interviews will play a big role in Deloitte's decision to give you an offer. If you'd like to learn more about group case interviews, check-out our separate detailed guide here.

5. Top behavioural interview questions asked at Deloitte

Behavioural interview questions asked at Deloitte fall into two categories:

  • Fit questions. These are generic questions such as “Why consulting?” or “Why Deloitte?”.
  • 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 Deloitte and other consulting firms.

Top 5 fit questions:

  • Why Deloitte?
  • 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.

6. Deloitte case interview preparation plan

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

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 Deloitte 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 Deloitte 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. Deloitte 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 Deloitte cases, you can use our BCG & Bain Case Interview Training ProgrammeDeloitte 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

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 Deloitte. 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 Deloitte 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 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 Deloitte, 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, Deloitte uses the same type of case interviews as BCG and Bain, so you can use that programme to prepare.

BCG & Bain Case Interview Training Programme

BCG & Bain case interview training programme

Any questions about Deloitte 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