I got pretty lucky tbh. Initially got rejected (twice!) by Facebook a few months ago with a referral at the company (didn't even receive a phone screening just flat out rejection email after viewing my resume). Received an offer from Microsoft and emailed them back asking if they were still interested in considering me for new grad hire. Did a phone screening 2 days later, onsite the following Monday and received an offer that Friday. I think this was exceptionally quick because they had to make a decision before my other offer deadlines but I was extremely impressed by how fast and thorough they were! There were three onsite interviews, each 45 minutes long. The first two were coding interviews while the last one was 50% behavioural (ex: "what's the biggest technical challenge you've faced?", "talk about a time you've had to push an idea despite opposition?") and 50% "simple" coding. The questions themselves I'd say were slightly harder than Google's onsite (got rejected by them a month earlier) but by the time I did Facebook I had done about about 200 Leetcode questions so I felt extremely comfortable with them. Actually at the beginning of each interview I had to tell them for the first 2-3 questions that I had already seen them.