This question is similar to designing and scaling a social network. Similar concepts apply.
Good overview: https://hayksimonyan.substack.com/p/system-design-interview-design-twitter
Great video on social network design: https://www.youtube.com/watch?v=S2y9_XYOZsg
High level solution: https://dev.to/zeeshanali0704/designing-twitter-a-system-design-interview-question-221e?utm_source=chatgpt.com