Finding freelance developer

Hi; could anyone suggest how or where to find freelancers for hardware and / or software development on ARM Embed platform?

In general every design house in your vicinity should be able to help you with this. If you don’t know any it could be wise to pop by a local hackerspace or a maker/IoT meetup, a lot of people around there that do freelance prototyping.

You could also try it at some of the online marketplaces, here’s a thread from 2011 discussing these, also with some results.