HN is lightweight in some ways, but also quite bad in others. For example, every single time you vote on anything, the site sends back a 302 redirect and then a copy of the entire page's HTML in response. This means that every vote results in a response that's usually around 10KB gzipped. As of right now, for me, voting on any comment in this thread currently causes a 14KB response and takes about 1.3 seconds to fini…
I assume you have JavaScript disabled, right? If so, can you give an example of a similar webpage that doesn’t reload the whole page to reflect your vote?
However when JS and AJAX is used, it's expected that it also avoids an entire full-page HTML response that goes unused. It can easily be a 204 instead.