It's a Rails app trying to load hundreds of different bits of data (emojis, comments, votes on comments, etc.), I'd honestly be more surprised if it were quick.

GitHub loads similar data and is also written in rails, but long GitHub PRs/issues are significantly faster to load.

It’s probably hammering the database right now.

These kind of things, by nature, are difficult to cache because the balance between “fresh” new content and how often they are accessed leans heavily towards having it served from the backend directly.

Ruby on Rails backend, I think.

Github is also RoR backend, and it's not this slow.