I found out about Mesosphere via Hacker News and applied through the careers portal of their website. Three weeks later I got an email from a recruiter. There was an initial phone chat with recruiting, a 4-hour take-home coding challenge, a follow-up call with an engineer about it, and then an on-site. The entire process took about 5 weeks, which was partially due to my own crazy scheduling issues. The coding challenge was practical, and the on-site was very typical of Silicon Valley: 4 x 45-60min whiteboard sessions with various members of the engineering team, lunch with potential future team members, and a chat with a founder.

The recruitment team reached out to me via email first and wanted to know about my future goals and interests. First phone screen so was your usual first phone screen interview (background, goals, do you know the company, etc). My second phone interview was with one of the lead engineers/managers which wasn't a lot technical, background check and my interests, after talking a bit with me he concluded that I was a good candidate to move to the next step which is the coding/take home challenge. He explained all that needed to be done and what they were expecting very clearly. After finishing the call he email me the challenge and all the instructions needed. The challenge consists in building a small web app (no backend required) using whatever stack you want to (I suggest you be familiar with React though). If you understand basic data structures and algorithms (e.g recursion) and have built apps from scratch you will do fine. Try adding unit tests to increase your chances. Don't spend days on it because ~4hs is expected. After sending back my code with documentation/README on how to run and explaining my stack I had another call with lead engineer which was a code review why I chose to do the way I did and a couple more general technical questions. After that the team decide if you are good candidate or not to be invited to visit the office in SF. I was invited to interview at the SF office, the recruiter team was very helpful to plan the flight and hotel to SF. The day of the interview be ready to 3hrs to 6hrs of interview process. You will interview with different team members where the interview can be from general Javascript questions to some basic algorithm/data structure and behavioral conversation.