jointhefediverse.net seems to be a commonly linked resource for directing people to join the Fediverse.
Curiously, it does not list Lemmy under the list of Reddit alternatives. Their GitHub README explains why.
Previous relevant discussion: https://lemmy.ml/post/78808
Yeah, I don’t expect it to scale well. Certainly not as well as Rust.
In terms of incoming federation, PieFed sites are dealing with as much activity as any general Lemmy instance. It’s not happened yet, but I suppose it’s possible that problems will become apparent if the amount of local users gets over a certain size. A limit on the amount of users per instance isn’t necessarily a bad thing though (it’s cheap, and hopefully easy enough, for someone to spin up another one).
What’s going to cause problems? Python, the db, redis or other?
It uses postgres for the DB - I think that and redis are designed to operate at very large scales, so it wouldn’t be them.
My guess would be that it’s something in the interpreted nature of Python - this seems to be why a familiar dismissal of PieFed is a concern about how it will scale.
That said, this site shows that Python is the most popular language for Fediverse apps (just), the likes of Mastodon are written in another interpreted language (Ruby), and I think there are more big websites running Python (with Django or Flask) than people realise. So I don’t know, really, I’m just following other people’s lead on this. I don’t imagine that any problems would be insurmountable though: an admin could restrict the amount of signups, or if new users mean a few more donations, they could just throw money at the problem (more cycles for one server, or splitting up tasks across multiple servers).
If you consider all AI-chat sites are running on python, I guess python scales with no issue at all