Instead of just one post, I'll highlight three posts.

https://lemmy.world/post/875584

https://lemmy.world/post/1035095

https://lemmy.world/post/1061471

The https://lemmy.world administrator team has been working with the Lemmy developers to fix issues associated with the currently largest instance of Lemmy in the Fediverse. July 1st was also the promised date where Reddit would cut 3rd party API access.

The most recent post is showing off some development progress with SQL statements that have been part of the bottleneck in practice. There's still plenty of performance issues of course, but the big problems have been touched upon and already have been fixed.