When I applied, it turned out they were planning a campus recruiting event in my city (Moscow) within the next two weeks. Unfortunately, I was on a trip at that time and couldn't make it.

Thus, they conducted one phone interview (with a recruiter) and invited me to a recruiting event in Kiev six weeks later.

There, they had two groups of interviewees coming at different times, each group consisting of six people. Every person would undergo three or four interviews, each 45 minutes long.

After every interview, interviewers exchanged feedback, and you listened to the HR representative who promoted Seattle as a place to live. After that, you proceeded to another interview.

After three interviews, they analyzed the feedback and decided who would stay for a fourth interview. If you weren't invited to the fourth interview, it didn't mean you wouldn't get an offer; I personally received an offer after only three.

The questions varied in difficulty depending on the interviewer, but overall, I found them harder than at other major companies (Google, Facebook). As usual, if you have ever participated in programming competitions, you have better chances of solving their problems.

I don't think I can disclose the exact question, but one of the interviewers actually asked two questions.

One was some kind of "real world" open-ended question, and another seemed to be algorithmic. The problem was that there was no solution, and even the interviewer had some ideas about it, but not the complete solution.