This was one of the most unintelligent processes of interviewing people I have ever seen in my career (PhD physics, 5 years in data science, machine learning). These guys do not screen for critical thinking or deep knowledge of machine learning algorithms. They do not screen for problem solving skills, which is what they should be doing when screening for data scientists. Instead they screen to see if you can write a few trivial coding questions that anybody can do after googling for a few seconds. I have had intelligent interviews before where they really screened problem solving skills. After reviewing their screening process I would suggest Facebook hire freelancers on upwork.com. 1 phone screening, just an introduction second phone interview, for further "technical" screening