I applied through an employee referral, and three days later got an e-mail from HR. The 1st screening was 2 different exams One for language and another one for math/statistics skills and sql, both examinations had a time limit and I found them quite interesting and difficult. After that I had to confirm availability for a phone screening with HR and then another one with the Hiring Manager. Questions where basic and needed a lot of knowledge on the area and challenges that the company face at the current moment. I was again ask to confirm availability for back-to-back interviews with 4 different people, including the hiring manager. I got an email from two different HR contacts with a bit of information on what each interview would focus on. People where very kind and made me feel on a conversation instead of an interview, but they had a lot of controversial questions, and got a good-cop bad-cop situation going on because the first interview was really difficult and the second not so much, the next one was really hard and the last was easy as could be. They asked me a lot about why facebook, what I wanted from the company, what I liked about my job, where I failed and what I'd do better. I had to show a lot of passion for user operations.