The Boston Consulting Group Data Analyst Interview Guide

The first step for me was a Python coding test on CodeSignal, and that set the tone for the whole process. It was four tasks on the same dataset, mostly very practical data-wrangling work rather than anything algorithmic. I had to do joins between dataframes, compute sums and averages after filtering on conditions like date > x, replace nulls with the mean, use an encoder and a standard scaler, round an age column to the nearest integer, and then make a price prediction and save the transformed result as a CSV. It felt like they were checking whether I could move comfortably through a typical analyst workflow in Python and pandas, not whether I could solve a tricky coding puzzle.

After that, I had an online case interview with a chatbot. That part was unusual: it described pieces of a case and asked strategic questions along the way, including graphic interpretation and what questions I would ask in an interview. At the end there was a one-minute case review video recording, so I had to summarize my thinking quickly and clearly. In a later interview, they also asked three SQL questions, a couple of basic ML questions, and two Python questions, then followed up on the qualification test and some resume achievements. That round felt more conversational and checked whether I could explain my own work, but it still stayed at a fairly basic level technically. I didn’t make it through in the end, so my main takeaway is to be very comfortable with pandas-style transformations, basic SQL, and being able to talk through case exhibits and your own resume clearly and concisely.