Meta Onsite System Design Questions

I am compiling system design questions for Meta onsite interviews. Two onsite coding rounds at Meta are quite similar to phone screens and are mostly based on questions. Behavioral questions are standard leadership principles questions. I could not find a compilation of system design questions from the past year, so I'm creating this list. Your contributions are welcome.

1. Ad click aggregation system
2. Top 10 songs played on Spotify (top-k problem)
3. Design a web crawler
4. Design a system to store images for Facebook and Instagram that would require 1000 uploads per second and handle duplication.
5. Design online chess
6. Design WhatsApp
7. Design a price alert system similar to camelcamelcamel.com
8. Design a proximity server.
9. Design YouTube.
10. Design the Facebook post privacy functionality. If I make a Facebook post, and I have 3 privacy options to choose from (Only Me, Friends Only, Public), design how you would determine visibility for any Facebook user (i.e., can a Facebook user see the post or not)
11. Design an online judge.