Google

The questions were mid complexity level. The HR never came back with results after the second round. The first interviewer was friendly. The second was not friendly, and I got nervous during the interview.

The interview process continued for over a year, and HR will not follow up. You need to proactively follow up with HR. They will keep you on hold and, after multiple follow-ups, will simply tell you that you are rejected.

Very easy if you know data structures and algorithms very well, plus creative thinking and some knowledge of system design. You are good to go. They mainly focus on data structure and algorithm questions and how well and optimized a solution you can