I applied through other source. The process took 2 months. I interviewed at Meta
Interview
First interview was coding (SQL and Python). No tricks but you need to be fast so train before hand, They give plenty of material and online resources so you can be prepared.
Second interview was a full day in house working on design problems. Plenty of whiteboard design exercises and coding,
I applied through a recruiter. I interviewed at Meta in Aug 2017
Interview
first round was coding round on coderpad and then there was an onsite interview at menlo park. coding was sql and python. in person interview was more difficiult than the coding round.
1 hour interview with python and sql questions,
then a day with 4 interviews on use cases in data. using sql and python, and designing a data warehouse.
the recruiter was very nice and explained the whole process, gave a lot of time to prepare yourself for the interview.
in general I like the interview proccess, everything was very clear