I applied through a recruiter. The process took 4 weeks. I interviewed at Meta
Interview
I had a recruiter reach out to me on LinkedIn. It was a very pleasant conversation. He said that he was going to set up a technical interview for me. It took about a month. They gave me lots of resources to look over and an outline of the interview in a email. The technical interview was two 45 min sessions with a 15 min break in between. One covering Python (or Java if you are stronger in that language) and one covering MySQL. The interviewers were very helpful and would give hints if you requested them. Overall it was one of the nicest interview processes I have been through.
I applied online. I interviewed at Meta (New York, NY)
Interview
Prepare technical concepts, and practice previously asked questions as much as you can find online. 4 rounds in the total process. It's easy as long as you just practice a LOT.
I had Python and SQL round for 30 minutes each. The interview was for 1 hour 30 minutes for SQL and 30 mins for python coding.
Completed 5 questions each but still got rejection email the next day.