Meta Software Developer interview questions

The recruiter reached out from linkedin. Then I was scheduled for a phone interview. One week after the phone interview, I went on-site for 5 more 45 minutes one-on-one interviews. The first one dedicated 25 minutes on behavioral questions. i.e. challenge, conflict, etc. Including the first one, three interviews had white board coding algorithm questions. The other 2 interviews were on system design. The algorithm questions could be found on leetcode and careercup. The system design focused on distributed system. Practice was the key. Though, I had about 3 weeks to prepare for the interviews, as a father of 2 toddlers, I could only have a couple of hours here and there. It's pretty hard to study when another pair of little hands are also banging the keyboards at the same time. With limited time, I focused more on the algorithm questions and did well on the coding rounds. However, a week after the on-site, HR informed me the decision to reject my application due to the poor performance on the design round. I didn't think I did badly on the design round, but with a large candidate pool, I guess they could be very selective on hiring. It's really a devastating feeling to see your faith controlled by some 20-yo. Still, I feel with more practice on the system design questions, it's not impossible to get there.