Pinterest Data Scientist Interview Experience — Five Rounds Interrupted by a Recruiter Conflict

I had a really bizarre interview experience.

Pinterest VO: it was originally supposed to be 5 rounds back-to-back in one day, but on the day of the interview the recruiter said there was a conflict. I only did three rounds, and the other two got rescheduled to two days later.

Round 1: use case / analytical system design. The interviewer was a DS manager. He laid out a simple problem statement and then had me share my thoughts — Pinterest wants to add a Carousel feature at the very top of the app, basically a horizontally-swiping design, which felt to me pretty similar to Instagram Stories. He asked what I thought. I first said I'd like to clarify the intent behind adding this feature — was it re-surfacing pins the user had previously saved, or was it pin recommendations, same as the original vertical layout? The interviewer just said he wanted to hear my thoughts. Then he asked: if after adding this Carousel, the overall page CTR drops, what's going on? I didn't catch the key point and didn't answer it well, and I'm not sure if the conversation just ran out of steam, but he ended up just having me talk about my recent project instead.

Round 2: hiring manager. His self-introduction was one sentence — my name is X, I'm a manager, I lead projects from 0 to 1 and from 1 to 100. Then he started asking all kinds of behavioral questions.

Round 3: 1/ coding — a jackknife variant, 2/ dataframe manipulation, 3/ how would you implement np.random.choice.

Edited to add: the stats round covered an experiment related to a billboard test. The cross-functional round was BQ (behavioral) questions.