Meta Software Engineer interview questions

Standard phone interview and an onsite loop comprising of 5 (3 Coding, 1 System Design and 1 Behavorial) interviews. The process was smooth and the interviewers were friendly and helpful. However, experience with recruiter was unpleasant. I never met the person (had a sub greet me on the day of the interview) and it's understandable at times. But after the interview, I just got a generic reject email. Upon asking for constructive feedback, the person was reluctant to share any. This was probably okay a few years ago, but in recent times, every company (including FB) takes time to communicate decision and feedback via a phone call. At a good company, I'd minimally expect the HR to exhibit people skills.

Just a very normal phone screen process. First we had 5-minute Introduction, then two technical questions, and ends by asking questions to the interviewer. The technical questions are answered on their codepad and no test cases were given. The interviewer spots to see any mistake in logic. Running time questions are asked also.