Three stages: phone, followed by first in person and second in person with presentation.
Fairly standard for a tech company, but the process was very fair and in depth. They know very much who they are looking for, so you need to know your skills and how you can bring value to them - but the interview is not harsh or intimidating.
As is the case for any interview - it will help greatly to do your homework and get to know the company and what they do. Don't expect a call back if you've never gone on the website or watched any of their promotional material.