Within like an hour or two pg emailed me asking me to stop. I didn't know it at the time, but HN was being run on a rusty potato and scraping the homepage every 5 or 10 seconds was causing significant load.
curl -N -H "Accept: text/event-stream" "https://hacker-news.firebaseio.com/v0/maxitem.json"
The potato with multiple eyes works to serve one of the more important and trafficked properties on the Internet.
I like HN, but it's really only important within a very niche subset of the Internet, and it also doesn't have much traffic. There's like a single post submitted every two minutes. That's not much.
https://www.reddit.com/r/TheoryOfReddit/comments/s2dvr4/the_...
Nonetheless, i suspect that HN probably is quite efficient, just based on what I know about dang. Even so, the parent claim was that it was popular and important, not that it was efficient