The interview process was really awesome. HR maintained constant contact and was super friendly.

I was referred, but I don't think that altered the process at all. It consisted of an online HackerRank coding challenge, a phone screen, and then an onsite with four technical interviews.

It's kind of unique that their coding challenge is a "best effort" kind of thing. You can do the easy/slow solution and get minimal points (I doubt it's good enough to move on), but it probably still feels better than totally flunking.

The phone screen was a bit harder, but the actual coding wasn't too difficult. The interviewer was much more interested in seeing how you handle edge cases and how you approach scalability.

The on-sites were difficult, and most of the questions were harder/more-involved versions of common LeetCode-type questions. Expect one question requiring detailed concurrency knowledge, and be prepared to explain how your algorithm can scale to larger datasets.

Multi-threaded token bucket algorithm