Design a microblogging service similar to Twitter. You may structure your answer using both verbal explanation and organized notes.
The platform should provide these core behaviors:
- Let users publish short messages.
- Let users follow or stop following other accounts.
- Show each user a home feed containing recent posts from accounts they follow.
- Remain responsive under heavy read and write traffic.
Your design should clarify and address:
- The main public APIs and data model.
- How to generate a user's feed: push to followers at write time, fetch on read, or a hybrid approach.
- Storage systems, caching layers, pagination, and ranking heuristics.
- Consistency requirements, including how soon a newly published post should appear in followers' feeds.
- Operational safeguards: rate limiting, spam and abuse prevention, and observability.