I applied through an employee referral. The process took 1 week. I interviewed at Meta (New York, NY) in Jan 2018
Interview
I took a phone interview with one engineer from Facebook. He began with an easy coding question and I solved it in 25 mins. Then he asked a harder question, and we only have around 20 mins left. We went through the solution. I was pretty confidence about this phone interview, however, for some reason, I didn't pass this round.
I applied through an employee referral. I interviewed at Meta in Feb 2018
Interview
Contacted by HR first and than scheduled a coding interview. The interviewer has a similar background with me and got to chat a little bit about both my project and how that related to current Facebook project.
I applied in-person. The process took 3 months. I interviewed at Meta (Mumbai) in Sep 2016
Interview
It took 3 months. Several rounds of phone interviews, Skype and onsite interviews. The QnA was tough and also the white board rounds were pretty difficult to crack. I would recommend to make sure you know the tech very well and are able to explain your work properly.