I was contacted by the Hiring manager after seeing my resume that was submitted fora different opening. Had a phone screen with a principal engineer in the same project. No coding questions were asked but had a great conversation on network management, latency and my work in general. Was scheduled for an onsite interview after 2 weeks. Had a short phone call with the recruiter the day before the interview on what to expect during the day. I was told that 3 rounds of 1:1 interviews were scheduled with a potential for that to be extended to two more rounds. Was specifically told that more than 3 interviews is considered a good sign. The recruiter also promised to get back within 48 hours with the result. First round of interviews was with a principal engineer. He let me use his development system to code. Along with the main coding question, was given two additional code snippets to find bugs/issues. All three problems were not overly had but had plenty of areas which lead to software design discussions. The next was a lunch interview with was very pleasant. Had an opportunity to talk about both work and life in Seattle. The last 30 mins were dedicated to a system design/requirements gathering question and was also asked to pseudo code the algorithm at the end. Third round was with the hiring manager. Was asked to go deep into a mutual exclusion problem that i had coded around 5 years ago. I had forgotten a lot of finer details of it and was finding it hard to recollect. He let that pass and asked me a coding question that i was able to code. The 4th round was with one of his peers. The hour was mostly spend on OS fundamentals with a coding problem at the end. Had a good experience overall and i was happy with my performance. Waited 3 days for the recruiter to let me know the result but all i got was radio silence. Had to convince myself that i didn't make it after waiting for a week. I guess their hiring standards are really high. One advice for other folks is to brush up on their past work to as much detail as possible. I felt i had missed out on the interview with the Hiring manager where i couldn't go deep into my past work. Another helpful tip is to ask as many clarifying questions as possible to their coding problems. Every one in the interview including the Hiring manager are able to device a problem on the spot and leave the details to us. It really helps to nail down the details before staring to code. Also beware that they can stop you at any time and pose a specific assumption for the problem that makes you change your approach and re-think all over again.