I can see how the AT protocol is designed to scale. ActivityPub works fine now because the community is fairly small, but it will reach its limits as it is currently designed. Its basically an event driven model vs a push and pull model. Sure a docker image can more or less jusy be deployed, but that simplicity is a ticking time bomb.
Running a relay is way more powerful than the author states though. You could do stuff like selectivly intercept and reject events before they make it into or out of the firehose.






Yeah i guess you could look at it that way. Each instance would have to scale horizontally to handle the load, which is waste.
I could be wrong, but my understanding is that ActivityPub is just a rest api contract that one can implement in order to communicate with the rest of the “network”. Its simple, but its such massive overhead to do this all via http. Pushing all your instances events to a dedicated stream and letting the other instnaces read it can be more performant and handle the load better. The downside though is who controls the streams?
IRC is the OG of federation, i am sure we could learn something from it and have federated networks that are in turn federated with eachother. I dunno, just thinking out loud here.