Chilling in the morning before I start my day job.

You mean like a list of all communities named "books" or "books.."? And then you could choose to visit individual communities by clicking on them?

The stack is great, I wouldnt want to change anything. Postgres is very mature and performant, with a high focus on correctness. It can sometimes be difficult to optimize queries, but there are wizards like @dullbananas@lemmy.ca who know how to do that. Anyway there is no better alternative that I know of. Rust is also great, just like Postgres it is very performant and has a focus on correctness. Unlike most programming languages it is almost impossible to get any runtime crashes, which is very valuable for a webservice.

The high performance means that less hardware is required to host a given number of users, compared to something like NodeJS or PHP. For example when kbin.social was popular, I remember it had to run on multiple beefy servers. Meanwhile lemmy.ml is still running on a single dedicated server, with much more active users. Or Mastodon having to handle incoming federation activities in background tasks which makes the code more complicated, while Lemmy can process them directly in the HTTP handler.

Nevertheless, scaling for more users always has its surprises. I remember very early in development, Lemmy wasnt able to handle more than a dozen requests per second. Turns out we only used a single database connection instead of a connection pool, so each db query was running after that last one was finished, which of course is very slow. It seems obvious in retrospect, but you never notice this problem until there are a dozen or so users active at the same time.

With the Reddit migration two years ago a lot of performance problems came up, as active users on Lemmy suddenly grew around 70 times. You can see some of that in the 0.18.x release announcements. One part of the solution was to add missing database indexes. Another was to remove websocket support, which was keeping a connection open for each user. That works fine with 100 users, but completely breaks down with 1000 or more.

After all there is nothing I would do different really. It would have been good to know about these scaling problems earlier, but thats impossible. In fact for my project Ibis (federated wiki) Im using the exact same architecture as Lemmy.

2nding @nutomic, that I'm really happy with the stack.

The one that seems really magical to me, is diesel. With it we get a compile-time-checked database, that's tightly integrated to the rust objects / code.

Every single join, select, insert, etc is checked before lemmy is even run, and it eliminates a whole category of errors resulting from mismaps.

Its made adding columns, and changing our data structures so much less error-prone than when I lived in the java-world.

Whenever we find that we'd want to do things differently, we usually do a refactor ASAP so as not to keep rolling spaghetti code. We've had to do this many times for the federation and DB code, and even have 2 major refactors that also add features ongoing. But luckily we've been able to stay in the rust eco-system for that.

As for UI, leptos didn't exist when I built lemmy-ui, so I went with a fast react-like alternative, inferno. Its showing its age now, so @sleepless1917 is working on lemmy-ui-leptos, which hopefully will supercede lemmy-ui.

!reddit@lemmy.world started to ban people based on upvotes

!buyeuropean@feddit.uk movement has motivated people to look around for European alternatives to Reddit