I'm not sure how this project in particular handle it, but i see quite a few project that handle it by simply using the "follower" for a user as their replica.

I'm not sure how this project in particular handle it, but i see quite a few project that handle it by simply using the "follower" for a user as their replica. Since the message is signed there is no risk of being alterated or forget, so i can get the message of user FOO from user BAR as long BAR is "following" FOO. This scale well since the more popular you get more peer can replicate your messages and post.