It is mentioned on author's website though. https://www.fornjot.app/blog/the-world-needs-another-cad-pro...

There is lots of interesting space between "hobbyist" and "can justify to spend loads of money", and I tend to find myself right in the middle of that.

Feels like an indie cad era is upon us. Plasticity, mart3d, antimony ..

A CAD application, especially one with a custom CAD kernel, is a huge project.

What I've always found amusing is that there are actually quite a few geometric modeling kernels and every one of them costs a ton. https://en.wikipedia.org/wiki/Geometric_modeling_kernel