Faced a deep technical challenge during the interview, asked to design a personalization algorithm for product recommendations. I walked them through feature engineering and model choices, which stressed me out initially. Luckily, I realized the structure was almost identical to a problem I had explored on prachub.com while prepping. The interview progressed through a behavioral round where they focused on my previous experiences, and I ultimately received an offer, but decided to decline after careful consideration. Overall, it was intense but rewarding.
No offer
Negative experience
Easy interview
Application
I applied through a recruiter. The process took 3 weeks. I interviewed at Instacart (San Francisco, CA)
Interview
The interview process went decently until my "onsite" which was over video due to the pandemic. I logged in and activated my video, my interviewer never activated hers and said she didn't want to because she was at home. We all are, show some respect and don't make me feel like a buffoon talking to a blank screen for several hours. Her audio was awful and without the assistance of seeing facial expressions and gestures, I couldn't understand her. She asked me one vague question about using conversion rate data in an A/B test and asked me to describe a model I'd build. I asked for more info about the type of data and she said "what do you think, if I said it's conversion rate in an A/B test?" I said I'd assume it is a binary purchase/no purchase set and asked if that was a fair assumption. She replied "if you think so", so I spent the next ten minutes describing a logistic regression model then she said "that's completely incorrect. How would you use logistic regression to predict purchase amount?" I replied that I was operating under the assumption that it was a binary outcome and she said that was a poor assumption. Then she said "how would you use logistic regression to predict a continuous output?" I replied that I wouldn't, I'd use linear regression. "But you said you'd use logistic regression, so I want to know how you think that would work?" She was very sarcastic and insulting. Implied I was dumb, although I had specifically made a point to explain and get her approval on any assumptions I was making. Very, very negative experience. Speaks very poorly of the data science team there. The recruiter asked me to apply again because all the other interview feedback was so positive but I have no interest. Would not accept an offer had it been extended. I really got the impression that my interviewer was sitting in a messy diaper and couldn't wait to get off the call to change it.
It was pretty straightforward. HR and then technicals. The technicals were a mix of statistics and math questions. Overall, it moved pretty quickly. My interviewer was quite late with no apology and in general not very friendly. I knew someone interviewing at the same time and they had a much better experience and recieved the same questions.
Interview questions [1]
Question 1
Suppose we wanted to launch 15-minute deliveries in a specific area where we already deliver. How would you statistically test the results?