In a current state of higher occupations, what all knowledge are we supposed to have to be best skilled developer ?

Question

I mean, can someone from industry explain me in detail or an quick overview of what kind of actual work do industrial people do in R&D regarding programming language development.

Answer 1

Your question is to broad to answer. There are transaction processing and decision suppport systems. Then there are embedded and integrated systems. If you are talking of system software, you are looking at computer architecture concepts and low level languages.