Mastodon.social is having trouble federating right now because another instance is lagging and m.s's delivery jobs are stuck in a queue.
I'm looking forward to #Pleroma, and hopefully other implementations, taking off. Maybe #Mastodon could improve by taking a look at how other implementations solve their issues. I'd like to see a reference implementation for #ActivityPub that takes more ideas from Pleroma than Mastodon, i.e. a small, light server with pluggable frontends. And I don't want to see new projects like #PeerTube and #FunkWhale and any others base everything they do on the quirks of Mastodon.