I wrote software but the company I worked for manufactured a small computer to monitor power for buildings. It had wifi and such.  
We used a &quot;contract manufacturer&quot;. The company was called Agility in NH (USA).  They worked out ok, they would get the components, build, test and ship out to customers (Direct Fulfillment).<p>We had to order components, though they stored them.  I think its more expensive than overseas manufacturing but the fact they were close was helpful.