I know that Lemmy is open source and it can only get better from here on out, but I do wonder if any experts can weigh in whether the foundation is well written? Or are we building on top of 4 years worth of tech debt?
It’s decent, but it isn’t scalable, at least not yet.
Right now the entire Lemmy backend is one big “monolith”. One app does everything from logins and signups to posting and commenting. This makes it a little harder to scale, and I wouldn’t be surprised to see it split out into multiple micro services sooner rather than later so some of the bigger instances can scale better.
I’d love to know where the higher level dev stuff is being discussed and if they’ve made a decision on why or why not microservices.
It's fine. Nothing impressive about it but nothing horrifying about it. Could use better testing and better documentation, it's pretty weak on both fronts. It's a pretty young/immature code base, hard to have much tech debt yet. Not like its core dependencies can be a decade out of date. But it's easy to navigate and understand,relatively speaking.
As long as the backend is stateless, it can be scaled to handle huge amount of users, at least in theory. IMO the main issue right now with Lemmy deployment is pictrs not being stateless. It uses a filesystem-based internal database called sled. Not only this make pictrs not stateless, you can't even run multiple replica of pictrs in the same host because sled would crash if the database file lock is already acquired by another replica. Someone with some rust skill should consider donating their time to add postgresql support to pictrs soon, which will greatly help making Lemmy scalable. Too bad I know nothing about rust.
I have a friend that's a lot more technical than me and he said that Lemmy's codebase is kinda messy and relies on libraries that are still in beta and have not been tested well in the real world (since Rust is a relatively new language). This was a few months ago though, I'm not sure how much things changed since it's been getting a lot more support and rewrote the front-end. The good news is it'll get a lot better as more developers contribute to it.
I think a lot of people assume that because it's written in Rust that means it has to be super stable but that really isn't the case.
Someone mentioned they had started out using websockets instead of http. I guess they’ve since migrated, but that design choice makes me wonder about the qualifications of the devs to make that kind of choice.
I think it will improve as more people get involved. The fundamentals seem to work fine. Haven't looked at the repository yet but I am planning to do so and see whether I can make a (small) contribution somewhere. Probably in the form of cleaning up some technical debt.
It's probably decent, but it is also worth noting that Lemmy was never really expecting the massive explosion of activity it currently has quite so soon.
The current code base was probably good for a small number of users/instances, but everything isn't doing quite as well now that there are thousands, or even tens of thousands rattling about the place.
Someone mentioned they had started out using websockets instead of http. I guess they’ve since migrated, but that design choice makes me wonder about the qualifications of the devs to make that kind of choice.