I submitted the solved task from the website.

After some time, I was contacted by a recruiter, and we scheduled the first phone interview.

The interview went smoothly. The second interview was the last one.

I was somehow very slow solving the tasks. One of the interviewers was laughing at my attempts to approach the problem; I do not think that was very professional. I think I got a little angry at the end.

Questions from the second interview are below.

Probability task: Given 2 black and 4 white balls, what is the probability of selecting 1 black and 2 white balls?

Given a file, how to select the 100 most frequent words.

Given a multithreaded code with a race condition, find a mistake and correct the code.

Having a very big array of ads, how to select k of them at random, so that the probability of each combination is the same.