Independent contractors for design and software seem common, at least in my circles. But I have never encountered anyone that does this for electrical or mechanical work. Does this exist?
@mattiem I used a audio DSP and amplifier board designed by someone who recently launched this company doing custom electronics design: https://zotec.nl/
Depending on what you’re interested in I also have a friend who designs audio electronics such as synthesizers.
For metal and wood fabrication I’ve found a few people that do it locally through Facebook Marketplace and have used their services.