Hi, got contacted for a DS interview by BCG Gamma. How much of the interview process revolves around machine learning/advanced modeling vs traditional cases? Best ways to prepare? Thanks!
I interviewed and failed. All interviews were pretty much cases but data intensive. Sample cases - you are working with a oil company. (1) you are helping them price oil (in real-time ) for all their gas stations in Texas . How will you approach it. What data you want to see. (2) citi bike in new york city. How you define the strategy to rearrange bikes between locations. (3) working with a grocery chain, how you will define their loyality program. What data you want to capture. How do you define a model to issue coupons to increase sales. Hope this helps.
Thanks for the response! I heard of people getting a take home challenge, did you as well? And which level were you interviewing for?
Yes. First round is take home challenge. And phone screen to discuss the take home project.
For preparation, try practicing cases. Like you would for any consulting interviews.
I did this interview very recently. It was case-based and he asked very interesting questions, here are my notes: Case Interview : client is facing a problem and we want to fix it w/ my experience, Design experiment . Context: fast moving consumer retailer: eg 7/11 or target. Local promotions for items on sale w/ discount Client is trying to evaluate the benefits of coordinated national marketing What is the optimal discount that should pursue All promotions at the client run weekly, meaning they start Monday and end on Sunday No canablization across products, all product sales are independent Price elasticity is linear. If you raise the price, demand doesn’t really drop. Question: Exploratory w/ Linear Regression to show price elasticity for each different product. Predict price elasticity. The first one was to formulate a linear regression model to predict units sold given price. Then you can use coefficient on the predictor price as an indicator of price elasticity. Meaning for a unit increase of price you’ll see w increase in Sales. Where w will probably be negative or very small positive. It would be small positive if the item is inelastic to price, for example, gas. For example, if gas price increases, volume will not decease as much as luxury products for example. He then posed a harder problem which I wasn’t able to solve, but given that we have a model for each product to predict units sold, and a budget for a whole store, how much should be price each item? I formulated it as a linear combination of prices and elasticity: $Product1 * w1 + $product2 * w2 + … + $product_i * wi <= BUDGET. How do you choose the prices now? This is a constrained optimization problem. THEN, he posed a very interesting question, albeit a bit flawed for the interview context, about RF regression. We take that same data for the linear model and fit it using a RF regression. He then said the client complained that the fit isn’t monotonic, or in other words, it has a flat spots and this is wrong. WHY? This is b/c the DT fitting routine recursively splits the decision space. In this case, ti just finds the median/mean of the points at the split and draws a straight line. regtree2.png . Therefore if you don’t have enough estimators in your RF, you will see the flat spots!
Wow this is not even data science, it's just analytics. No deep learning and AI? Come on... BCG must be a joke. The regression tree question is interesting though... But still it looks like their job has no coding and no hardcore ML.
Thanks for the response! What level were you interviewing for if you don’t mind me asking?
BCG cares more about your looks. If you look skinny, upper class, they're way more likely to hire you.
How do you do the hackerrank test? I solved it and passed all test cases still got a reject
Hey! Could I please DM you regarding the Hackerrank test?
Why so? You did all 9 questions and still got reject? If they still reject, then I would think it as dodging a bullet
Has anybody had the business case for bcg gamma? I have one in a few days and would like do get a sense of what it is about
Hey, can I DM you about the rounds after hackerrank?
Hey everyone, I have an upcoming interview with BCG gamma. Can anyone tell me about thr hackerrank test ? Thank you !
Hey, we’re you able to get post through hackerrank? What’s the next tech round like?
Update? I have mine as well
Curious too. Tried to break into MBB a while back
Why? And why you are still in msft?