This is really impressive and I love how it came into existence out of necessity.
Could you share the application that you're using this backplane for? Is it a (very expensive) hobby project or a real world use case? You don't often see projects with a 12 layer PCB where the routing isn't critical in terms of reflection.
It's for a 4096-node cluster arranged in a 12-bit hamming-distance 1 graph. If you know what I'm talking about please don't spoil it for the others.
Yeah, it's a very expensive hobby project, but I can see some applications for similar pathological backplanes and BGA escape routing. Of course it doesn't do impedance control, length matching or differential pairs, but this could be useful on a _very small subset_ of _very complex boards_.
Basically I accidently stumbled into one of the hardest routing problems I've ever seen, and decided to build an autorouter. And that might be useful for other people.
Could you share the application that you're using this backplane for? Is it a (very expensive) hobby project or a real world use case? You don't often see projects with a 12 layer PCB where the routing isn't critical in terms of reflection.