Not dang and not the person you are asking but there is no CDN. HN is just two servers running BSD one active and one standby. HN is all text so there is not much bandwidth usage.

I did an experiment and linked from HN to my lame blog site and disabled all my anti-scraping measures. Even with all the bots I did not see that much traffic. I suspect some people are specifically being targeted by very poorly configured or very poorly written archiving scripts. Just one example thread discussing this with someone on HN [1]. Each case of being targeted will require looking at generalized characteristics but most are easy to stop in my opinion and experience.

[1] - https://news.ycombinator.com/item?id=48416693

And the backup is field-tested to fall over within a few hours of the primary ;-)

<https://news.ycombinator.com/item?id=32048148>

<https://news.ycombinator.com/item?id=32031243>

(AFAIK that specific failure mode has in fact been addressed.)