[quanto]

There are many good common sense answers in this thread: parallelize the runs, use faster (but more expensive) local runs, have a better model (physical or digital) to reduce the runs.

To answer your specific question, Shenzhen is a good place to work on hardware, but it is not like you just fly in, and people start building for you. Your own lead time (establishing yourself there) will likely be in weeks if not months. This is from my personal experience in Shenzhen and other hardware founders'.

If you want to build the prototype faster, identifying the bottleneck is a great start. Which takes most time? For up to medium complexity, PCB fab (the board itself) is the most time-consuming part. Anything more complex, it could be the SMT assembly. Each part of the entire process can be optimized: PCB fab can be done in-house quick (chemical etching, CNC machining, etc). Assembly can be optimized too (solder reflow oven, solder paste stencils, etc) on a small scale. I would estimate a batch of 5 boards of 50 SMT components each can be produced under 8 active engineer-hours. That's your entire prototype in a work day.

Do you have professional/academic training in electrical engineering? EE is no less complex than CS, and perhaps studying up the entire process will help you identify what's possible and what's the bottleneck.

[HeyLaughingBoy]

> 5 boards of 50 SMT components each can be produced under 8 active engineer-hours

Far less! That's about how many boards of similar complexity I could hand-stuff and reflow in an hour!