Note that here DIY means designing the chassis, the drive loader mechanism, PCBs for backplate, power distribution (including crimping dozens of power cables), modding PCIe cards to fit.

It's not a boring "I bought a Chia mining server and inserted lots of hard drives" build.

You should watch the video before commenting; in the first 10 seconds it’s explained that everything is built from scratch, including chassis.

I’ll just leave this here: https://news.ycombinator.com/item?id=46512881