I applied to the position by e-mail and got an e-mail requesting me to solve a problem within one hour. The exercise wasn't really hard but you must be aware your solution have to be efficient, their systems handle a huge amount of data and must be really fast.
Then I wen't to the in-person interview in São Paulo - Brazil. I had four interviews in a row, about 40 minutes each. Some interviewers were developers, other were managers.
All of them asked technical questions and I had to write code on a flip chart, explaining everything to the interviewer.
Three of the interviewers asked me to write code and one asked questions about software architecture.
The questions aren't really difficult, but you will have to write code in a flip chart and keep the telling the interviewer everything your are thinking/doing.
Only one interviewer asked me to write the code in Java or C++. The rest of them allowed to choose any language.