Older HN users may recall when busy discussions had comments split across several pages. This is because the Arc [1] language that HN runs on was originally hosted on top of Racket [2] and the implementation was too slow to handle giant discussions at HN scale. Around September 2024 Dang et al finished porting Arc to SBCL, and performance increased so much that even the largest discussions no longer need splitting. The server is unresponsive/restarting a lot less frequently since these changes, too, despite continued growth in traffic and comments:

https://news.ycombinator.com/item?id=41679215

[1] https://paulgraham.com/arc.html

[2] https://racket-lang.org/