分享一个Pinterest DSA电面的dp, 1hr Technical Virtual Phone Interview : 1道sql 2道python 2道experiment.google и\n\nsql: 给了三个table：events (pin_id, date, events including impression, click, number of events), users, pin_classificaiton(including pin_id, pin_format, e.g. video, static etc.) 问: calculate the click through rate for each pin_format for the new users in US? new users here are defined as users whose sign up date is within 30 days of action date.\npython: 1. 给了一个table including pin_id, category id, time spent, pin format 和一个dictionary of category id & name; 问：find the category name with highest average time spent for video pin\n给了个dictionary {user1: [1,2,2], user2: [1,2,3]} find the average of number of unique pin of each user\n\nexperiment：给了一个case, increasing video pins to increase user engagment, 问：1/what's the hypothesis, and alternative hypothesiss 2/给了个table results 问how to interpret the results including metrics + p-value