The "Twitter-scale Mastodon" is separate from this OP article, which seems to be a small beginner tutorial that's more of a Facebook clone tbh (it has friend requests [0]).
In any case, this title is very misleading: Rama itself is not open source [1].
> mastodon, our Twitter-scale Mastodon implementation in only 10k lines of code (available on August 29th).
so did you just jump the gun?
p.s. the 361 comment thread to save someone the trouble of "what's this?" https://news.ycombinator.com/item?id=37137110