Perhaps they've optimised for the normal levels of traffic they receive, not unanticpated spikes. That's hardly an embarrassing choice.

I'm not talking about the administrator of this instance, I'm talking about how mastodon is fundamentally designed. Even an iPhone could probably serve the (static) text of Tao's post to a million people on a 5G connection. Computers are fast.

I run Mastodon on a $5 VM. If I hit HN homepage, my site will probably be slow as well. I don’t see how that reflects on Mastodon though.

what am I saying is that there's a way to design a site on a $5 VM that serves static text that wouldn't be slow even if it was #1 on HN.

if you disagree with that then we'll have to agree to disagree.

Feel free to share your know-how https://github.com/mastodon/mastodon

Mastodon's architecture inherently does not prioritize speed of first page load. Any PR would be rejected :D

I thought what and when to cache was one of the hardest problems in computer science.

Something like Mastodon is likely 90% reads, or even more. How often is the OP editing their post? When they post, cache it. Kind of like what I did by including it in my original post. Caching is a hard problem because sometimes invalidation results in serious consequences, therefore knowing when to invalidate becomes potentially intractable. In this case there would be few, if any.

it was cache invalidation, and naming things. Just throwing stuff in cache is easy.

Why would it be difficult to cache static text?