CAD/Design software for panels

For 2D work I think Inkscape (free software, https://inkspace.org/) is popular, it can generate DXF files. Personally I'd code it up in Postscript and convert from .ps to .dxf, but I prefer code to WYSIWYG as its easy to parameterize.

For instance I've a postscript script that can generate a dovetailed laser cut box of any size by just changing 3 numbers:
box_example.png