Varnish would do just fine, ditto Nginx, or they could have used cloudflare or some other service.

The funny thing for me is that they make it seem as if 10K concurrent users is a 'big deal' for a bunch of static pages. If you're not interacting in real time a little bit of caching or page generation will go a long way towards being able to serve up a huge number of viewers / participants.

I've had 10k concurrent users on a bandwidth-intensive app served statically from 3 $5 digital ocean droplets using nginx. CPU usage and memory usage were not that high. I agree it's not a big deal.

This was exactly my reaction -- while nice that they could get a solution in a few lines of perl, quotes like

> During the day we improved and deployed this same code to the MagPi site including some horrid hackery to cache popular GET request combinations.

make me think they would have been much better served using a pre-existing solution (probably Varnish) that's built to do exactly this. This article reads like a major case of reinventing the wheel.