The whole process takes around 3 weeks to finish. It was quite a pleasant one.

First, there was a phone talk, not quite formal, just simple background discussion. Then, there was one round of face-to-face interview with the manager and two of their engineers.

A bit of whiteboard coding, not specifically related to data structure and algorithms, though. Overall, it was pretty easy. One possible reason is the squad I'm in is not exactly the Analytics group, so they didn't specify much on data science knowledge.

It seems they were pretty interested in my knowledge in probability and statistics, apart from technical things such as cloud platforms and programming.

Given a list of user records, select out unique users in one city.