Boston Consulting Group Data Scientist Interview Questions

I submitted the application online and then got the invitation email to one-way video interview. The video interview consists of three part. You will have one week from the data you are invited to take the interview.

First round was a phone interview, here the recruiter explained what the exact position was and asked one technical question. Second round was a Data Scientist hiring coding test on hackerrank, I failed this test. The hackerrank environment was very annoying for the type of questions you get asked.

Applied Online. Then got Virtual video interview. Guessing the next stages are phone interview and onsite with interviews being case-based and how to understand how to use data science techniques in the case.

This was for a GAMMA Consultant position, which is for BCG's data science arm. Went through three rounds before getting cut: 1) Recruiter phone screen, which was very casual and low-key, mostly explaining background, fit, and a project on my resume. 2) Technical assessment, which was administered through HackerRank, composed of a series of programming exercises to pre-process data and train a model, as well as two ML / time series theoretical questions at the end. 3) Technical case interview via interview, with a GAMMA Data Scientist. The case can vary depending on the interviewer from what I heard. Ultimately, I needed a lot of clarification in the case and was too slow on developing analytical solutions. GAMMA is looking for the best of best of quantitative minds as they are competing with QuantumBlack. Those skilled enough to get through the technical case move on to a business case, and then from there go on-site to either Boston or LA to do multiple rounds of additional technical/general case interviews. A very intensive process overall.

The first round was a hackrank test where my coding skills were put to test. Once you get past that, the interview contained series of cases containing both Data Science and traditional strategy. I had a total of 6 cases (3 DS and 3 strategy cases). The overall process was quite seamless. The HR was very helpful, especially with feedback and preparation for next rounds. The cases were quite interesting and challenging which made the interview exciting.

They messed up stress interview with the technical interview. I was asked to spend several days to finish an analytics case (a very simple case similar those in Kaggle) before the case interview. A junior interviewer from the BCG Gamma in Boston interviewed me. He was obsessed to play a tough 'CTO' of the client, although his understanding of Data Science stopped updating about 3 years ago. Sometime, he just didn't listen. When he realized his arguments were invalid, he was angry. In the end, I felt like that they were probably used the 'case interview' to collect some analytics notebooks for their daily works.

The overall process is: HR Telephone Screen, Technical Case Interview (Homework) with Presentation - 1st round, Consulting Case Interview - 1st round and Final round in the Office. In this case I will focus more on my personal experiences coming from a tech background. HR is nice and they are responsive during the process, however they seem to be flying high with applicants using the BCG brand name so there’s a pipeline of candidates. (It took them 4 months to schedule/reschedule the 1st round so I guess HR rocks!) Cons: 1. The BCG brand name comes with the ego and attitude from its people. This is quite evident in the interview process. One of the interviewers was quite arrogant, egoistic and racially biased, when confronted - unapologetic. In general, interviewers are meant to push you to work harder and test your logical thinking to gauge your true ability. However, this interviewer was a perfect example of those with big titles but no manners. 2 minutes into the interview process, he asked about myself and motivations on applying, after handling that well, he picked up on certain answers to dig deeper into my prior experience. He rudely interrupted every single sentence I said during the fit questions. The tip off point was when he insulted me for my prior technical experience questioning the choice of technology stack. He did not trust a single word I said, and since he was rudely interrupting he missed half of my answers. For example, when I asked what you do at BCG Gamma “We work on cases just like the homework case and charge high fees for that” or when he decided to probe my prior experience by asking “Why would you use this framework, it should only be used for xyz (because I’m saying so!)” 10 minutes into the interview and I am appalled at how rude this interviewer is, so I decide to confront his actions. He dodged that twice and insisted we move on. The arrogance shown by the interviewer led me to disconnecting the phone call without presenting my homework case and withdrawing from the interview process. There’s similar reviews on this forum of such behaviour, I wonder if the interviewer reflects a similar behaviour to clients or has a split personality. 40 hours of hard work without any appreciation or acknowledgement in the bin. This was raised to HR but they seem ignorant as they have a pipeline of candidates willing to work in such conditions, they claim the interviewer was just “trying to have a conversation” and they have no recordings of the conversation so they trust what the interviewer says. 2. The work they do is mostly PoC’s, there’s no tangible end-to-end transformation work as GAMMA is a practice set up primarily to lure clients into signing off data analytics projects. If you are really good at it, the tech firms are the best place to be. GAMMA is way below the top tier tech firms and hot startups list in terms of standards. Suggestions to BCG: Take action on interviewers regardless of their titles or academic credentials, this person should have been let go a while ago for the horrendous behaviour and the countless interviewees who have suffered because of his actions. You might end up becoming the next Uber, it only takes one scandal! Hope this helps someone avoid a trap

First, I had an online coding challenge in Hackerrank. It was pretty hard and time was not enough. After the challenge, there was an HR screening, leading to a virtual technical case interview. After that, they called for an on-site interview, 2 technical cases with managers.

Took 2 months to get back after application. Sent a data science challenge on hackerrank. Given a dataset which we cannot even see properly on hackerrank, build 2 ML models and answer insight related questions within 2 hours. It made no sense. The dataset was in raw form (transaction level data), had to be studied and converted into features and target, split for training/testing and report accuracy. This is not how a data science task can be completed.

So I was contacted by BCG and asked to apply for a Data Scientist role at BCG Gamma in their Toronto office. After the phone screening, I was asked to prepare for a case study interview. The HR was professional in communicating and providing me with the necessary information. The case study was a 30 minutes video conference, with one of the senior consultants (a different team - more business oriented). The case study was quite simple. I needed to calculate the return of an investment, based on two scenarios, and provide some analysis on what are the non-economical pros and cos of each approach. I did the calculations, and provided right answers to both cases, and chose one which was more advantageous. The interviewer, however, was extremely unprofessional. He was 6 minutes late (it was 30 minutes in total), and he had some food in his mouth when he was talking to me! Imagine you have prepared for this for a few days, and this is the first impression they give you. By the way, I did greatly in the interview, with no major flaws in my analysis, as the interviewer this not question any of my approaches, and the problem was quite easy. But, the funny part is that I got rejected after 2 weeks with a template email! They provided no information about the reasons I got rejected. I sent several emails and insisted for information. HR called me, but they had no information in my file either! The only reason I can think of is that the interviewer was not in a good mood that day!!! Very unprofessional and insulting experience.