The whole process took over 4+ weeks. Recruiter reached out and then set up the first phone screen with the recruiter to go over some very basic questions. Then the waiting game started. It took 2+weeks to have the initial phone screens - 1 with designer for reviewing your work, and 1 with designer to have app critique. The talk was pleasant and from the feedback I received, both of my interviewers have enjoyed the talk with me. However, I am rejected for the in-person interview. Why? I think it's because I have too much experience.
For ux/ui designers, if you are a new grad or have very minimum experience, then yes, FB is for you. why? Let me tell you more..
I have quite a few connections in FB design departments and from the informal study I conducted, it appears to me that they want young, very young designers who either newly graduated from grad school or have very limited experiences (freelance or any unknown workplace experience). Even though FB claims to flat the org by not giving any title on the position, which could give you an impression that as long as you are the talent, they will hire you. But the ugly truth is that they do have certain level needs hiding behind the hiring. They want their designers to be "shape-able" and "control-able" and they want you to be there and do one small design project, such as a nav bar or a comment box and of course.
So if you are experienced, coming from a solid leading designer background and have been doing lots of hands-on work and giving directions, turn around and do not expect FB would take you. They have design managers who will do so, and then they only want junior designers. So if you are not a design manager, but want to be one, sorry, this is not the place for you.
Now you see, FB Design is quite interesting and this place is really just hiring new-bees. So my 2 cents would be save your time/energy, and stay in your current position with your current company for another couple of years. And when you ship lots of solid products, go to Apple where experienced people and only experienced people are appreciated.