Depends, of course. If one is original, inventive and noticeably smart with at least an MA degree then the ideal job would be working in an R&D department.

If more of a scientist mindset focus on the research side and if more of an engineer focus on the development side.

I came across an engineering agency awhile back in my city that is kind of a multi-disciplinary (hardware + software + design) group that enables companies that maybe cannot justify a multiple team member R&D department a place they can outsource development of their out their kinds of ideas.

This kind of agency might be most satisfying because of the variety of challenges and industries.