Bytedance Intern Data Scientist Interview Experience — Round Two's Same-Day-Duplicate SQL Question

This is my write-up for the second round of the TikTok DS interview (I also have a write-up for the first round, but I won't link it here).

The interviewer gave a brief self-introduction.

Then I introduced myself and walked through my resume. They dug into things like how I did data preprocessing, how I handled the bias/variance tradeoff, and how I chose performance metrics, and then briefly dug into the business context.

A hypothesis case: Combining it with my most recent internship experience — if your company were about to launch the product I built, how would I go about researching it?

A normal-difficulty SQL question: They reminded me to watch out for duplicates. The question was to output the total number of users who registered and posted on the same day, and the thing to watch out for is that a single user might post many times in one day.

A case question: Building on the simple metric from the previous SQL question, they asked how I'd analyze ways to improve creator engagement (including but not limited to the new-user-related metrics I'd just mentioned).

Reverse interview: I asked them to walk me through the current project their team is mainly working on.