1) Skype call (with future supervisor); 2) Test assignment, submitted via email (I sent a link to Google-doc, where my solution was provided); 3) On-site interview (probably with some extra test assignments); 4) Offer / rejection.

Before interview - there is several questions on the company's site. Several sections with independent interviewers. About experience, maths (statistics), programming (basic algorithms, distributed systems, etc), Linux/Network/Hardware (basic things), Project and People Management, etc. In general 2 interviews, might be with home tasks between them. All process took about 2-2.5 weeks.