I recently used their sister library (build123d, same devs) to build a rotary slide rule bracelet for multiplying three-digit numbers. It was a great experience and wouldn't generally be easy to do with Fusion 360. My bracelet gets quite a lot of comments when I wear it in public. :-)

Here's an IPython notebook with lots of pictures so you can see how the different operations come together: https://github.com/gcr/sliderule-bracelet/blob/main/version-...

build123d is quite different stylistically from cadquery, but this should give you the flavor of programming-oriented CAD at least.

My last project involved making a cosplay helmet. I modeled the shell in blender, it was a low poly design, so I exported it to an OBJ, then put together some Python to load the OBJ, give the triangles some configurable thickness etc. Then I used it to explore how to print the helmet in such a way that the outer surface would be too clean to tell it's FDM printed, without needing to do any sanding.

Initially I explored having cadquery put a number on the back of each triangle and I'd assemble it like a puzzle, but that didn't work out. Eventually I figured out how to cut it up into parts that would also eliminate the need for painting and outer surfaces would be clean, and because it was in code, changing which part a triangle belonged to was a matter of moving the corresponding index into another list.

I probably could've managed it all in blender too, but being much more comfortable with code, it was easier for me to play with normals and manually turning each piece into a solid.

I also go for it for functional designs because, again, tweaking code is more comfortable to me than dealing with constraints and sketches and multiple planes in, say, FreeCAD.

I'm working on a CAD kernel in Rust with a frontend either as a Blender plugin or a Blender fork (leaning towards fork at this point) It's not at all ready but I have reached first part status (before going back and rewriting a large chunk of the kernel)