I applied through an employee referral. The process took 2 weeks. I interviewed at Mirantis in June 2015
Interview
There were three stages of interviewing - two calls with potential manager from Bay area and with storage expert as my background is storage. Generally, very high-level questions. Third one (actually, first in sequence), was a live lab with 33 tasks to do. They send a link to custom lab environment, time constrained, while general Linux knowledge checkup is available for everyone just to try it.
During calls, they mentioned probable fourth round of in-person interview that would require me to travel abroad, but in real, that round hasn't happened.
I applied through a recruiter. The process took 3 weeks. I interviewed at Mirantis (Mountain View, CA)
Interview
Combination of emails, phone calls and in-person interviews. Called and spoke to a recruiter and she placed me in touch with the hiring manager. Had a great call with the manager so he put me in touch with the Director and VP. Had a call with the Director and that led to an on-site interview with everyone at the company(just kidding, although I did meet a ton of people.) The interview consisted of mini-interviews with the manager, developers, support folks and the Director and VP. It was very relaxed and people were genuinely engaging. It was the first interview where I felt that they wanted me to succeed, wanted me to tell them everything I knew so they could really go to bat FOR me, unlike other interviews where they want to see what you don't know versus what you do know.
Prior to this interview I had received multiple other offers from other similar companies but when the interview was over, I really felt something special about Mirantis.
Interview questions [1]
Question 1
Based on OpenStack architecture and Linux fundamentals. There are some behavioral questions as well. If you know you're stuff, you'll be fine. If you try and fake it, well, there going to know, these guys are the best in the business and you're not going to snow them.