I have made many designs that I would consider "professional grade", but in reality they are still just prototypes. I have used professional board fabs and professional population, but what I haven't had the ability to go through is actually turning that product into a commercial product.
What is needed in order to take the product across this large last step? I can think of obvious things like FCC/CE testing, case design, marketing, distributors, etc. but I am sure there are other things that aren't thought of until going through the process a time or two, as an engineer, what are these things that would come up?