The process began with a technical 1:1 phone screen. This part is not very difficult, they test basic algorithms and data structures knowledge. You have to code online and in real time with the interviewer using collabedit.
The onsite interview was exhausting and unnecessary long, I got there around 10 am and left at 5 pm. I was interviewed by 10 people in 5-6 sessions. The interviewers were nice in general and they tested: technical communication, algorithms, data structures, architecture/design and culture. I only failed to complete 1 of the questions but that was enough to get rejected.
Overall it seems like a good place to work at.