Technical phone call, 45min, and they type the question on a interactive board, you type your codes below, they challenge your answer, you answer some follow-up, but you need to keep communicating with them because even though you solve the coding problem but with a bad communication, you'll still be rejected.
I applied through a recruiter. The process took 3 weeks. I interviewed at Meta (Washington, DC) in Oct 2018
Interview
Spoke with a recruiter talking about general process, then technical phone interview which was 45 minutes to work through 2 technical coding questions. I admittedly did not prepare enough for the technical interview portion and stumbled through the solutions, but was able to eventually get the answer
I applied through a recruiter. I interviewed at Meta
Interview
A recruiter reached out to me. I sent my availability for a phone screen and this is when the troubles began. First, I never heard back from the recruiter again. Ever. The technical phone screen was still scheduled however, and I prepared for it as best I could. On the day of, the interviewer called over 20 minutes late and was very difficult to understand. Because of the delay I had little time to implement the algorithm he asked me about, which I implemented anyway (and my implementation was the optimal one!). He seemed very confused by simple logic (such as and statements) and multiple times questioned if my code would work with input even though I proved it would work. By the time I could ask him questions, I had to go due to an urgent event that I had scheduled (and he wanted me to stay on the call for another 20 minutes to make up for the lost 20 minutes earlier from his late call). Needless to say I was very unimpressed. I never heard back from the recruiter again, despite multiple emails. This entire experience was very confusing, since I'd had a very positive experience the year before.