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.

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.

Now that you know what to expect in Deloitte interviews, let's discuss the skills you need to develop to impress your interviewer.

6. Become really confident at maths

Deloitte will test your maths skills during the case section of your interview. It is therefore difficult to succeed at these interviews without being confident in maths.

Unfortunately, it is extremely common to have rusty maths skills when you start preparing. In our experience, candidates who end up getting a job in consulting take some time at the beginning of their preparation to brush up their maths and regain their confidence.

We find that making this initial investment is really worth it. This is the first step candidates take when they enrol in our BCG & Bain case interview training programme. We have also put together a few maths tips here which you might find helpful to get started.

As we mentioned above, Deloitte uses the same type of case interviews as BCG and Bain and you can therefore follow the same training programme if you prepare for Deloitte.

7. Develop a consistent method to crack cases

One of the challenges of interviewing with companies like Deloitte is that you will have to do about five before getting an offer. For many of these interviews you will get a case that you need to crack. You therefore need to learn a CONSISTENT way of cracking the case.

As mentioned previously, the good news is that candidate-led cases can be broken down into very specific types of questions: situation, framework development, framework exploration, quant question with and without data, creativity question and recommendation. If you find an approach to consistently crack each type of question within a case, then that means you will be able to consistently crack the case overall.

At IGotAnOffer, we were frustrated with the inexistence of a consistent approach to solve case questions when we were preparing for interviews. This is why we created a step-by-step method to solve cases that we teach in our case interview training programme.

Developing a consistent step-by-step approach will enable you to develop HABITS. And having developed these HABITS during your preparation will enable you to focus on the case at hand and to consistently crack the questions interviewers throw at you.

8. Practice cases out loud

One important aspect of your preparation is also trying to reproduce the conditions of a real interview when you practice. A great way to achieve this is to do case interviews with friends or with former consultants who do coaching interviews.

However this isn’t always possible and you will have to do some cases by yourself. In these situations, we would really encourage you to practice out loud. This means you should both play the role of the candidate and of the interviewer. In practice, that means you should ask questions and answer them out loud in the same way two people would do in an interview.

This will feel odd at first. But trust us; it actually makes a huge difference in your preparation. This is because THINKING about the right answer is only half the battle in case interviews. The second half is COMMUNICATING your answer in a clear and structured way. If you don’t practice out loud, you are only practicing half of the skills required to be successful. We really encourage you to give it a go as in our experience candidates who use this approach are much more likely to get an offer.

9. Learn from every mistake you make

Finally, you should really focus your preparation on quality rather than on quantity. Sure, there is a minimum number of hours you need to put in to develop good case interview habits – probably ~30h+. However in our experience, successful candidates find it more valuable to do 20 cases and to learn as much as possible from them, than to do 40 cases and to not learn much at all.

The best way to achieve this is to keep a notebook where you write down your mistakes at the end of each case. You should go back to that notebook on a regular basis and remind yourself of the things you have learned. This will enable you to avoid repeating the same mistakes twice and to make sure you actually progress as you do more and more cases.

A good way to check that you have actually progressed is to redo some of the cases that you did at the beginning of your preparation after a while. For instance, after you have done case #20, you could go back to case #1 to make sure you are not repeating the same mistakes. This way you can be sure that you are on the right track and actually making progress.

Additional resources

If you would like to fast track your case interview 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 therefore use that programme to prepare for Deloitte.

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