I think there is a place for a smarter algorithm than "ORDER BY date DESC", but one that is not designed to manipulate users into addiction.
For about a week they made a change that prevent that chronological timeline from being the default, but they reasonably quickly rolled that back. https://www.theverge.com/2022/3/14/22977782/twitter-default-...
even when following too many to read everything, i preferred chrono because it would yield a coherent slice of what was happening. an unbiased sample.
twitter is basically a medium for conversation.
imagine there's a large party. would you rather listen to an out-of-order "most important" set parts of the conversation, or just a slice of conversation from a particular time?
well, actually, both can be interesting, but generally the slice is more coherent. :-)
1. Insertion of tweet to tweets table.
2. Insertion of that tweet-id to the home timelines of all that user's followers.
3. Insertion of that tweet-id to the user-timeline of that user.
On the read-path, if I'm not mistaken, the only join that happen is between the requested timeline and the tweets table (which is replicated across cluster of machines but not partitioned, or at least I remember reading that was the case not many years ago)
I then use tweet deck which shows a column of tweets per list.
As these are separated by subject and are chronological, it makes it far easier to follow.