Most likely the HN Hug of Death® had gone into effect. It's capable of incapacitating any sort of system without load balancing as soon as that system is linked from the front of Hacker News.
There must be quite a few hits on your website when HN links it. nginx out of the box can handle quite a lot of connections, assuming that it isn't trying serve something too complicated on each one.
Since then it has been reappropriated widely on HN and Imgur and any place where people gather and unwittingly cause a denial of service with the best of intentions.
I have to say, it is quite fun watching words, phrases and ideas being made up on the fly at a prolific rate these days. I can still remember reading about memes in a Richard Dawkins book and a few years later the concept was coerced wholesale by the internets. I still remember thinking "what the fuck is a roflcopter" and then suddenly achieving enlightenment. My granddaughters were born with thumbs that can doom scroll.
Nowadays are properly weird and will continue to get weirder. Despite that it will also continue to be normal.
You and I both! It's fascinating.
Dare i say, a cDoS
Probably around then time when reddit really started to take off, so I'd guess early 2010s.
HN itself runs on one average sized server. This looks like a blog serving static content which should never go down if you put something like CF in front of it.
It's capable of incapacitating any sort of system without load balancing as soon as that system is linked from the front of Hacker News.