Mostly I have seen, that experienced programmers from the UNIX or Windows world are totally unable to build even small applications on a microcontroller.
thats because they have no knowledge of the hardware.

E.g. a simple program to switch 8 relays was built with 8 variables to represent the state of every relay. These are not defined as "bit" but as "signed int"
The result:
Almost all ressources are gulped already after the first 10 lines of the whole project.
That is none sense, because they either use bitfields or Embedded Language Extensions which they can't program without it.

Thus assembler experience was needed to program in C reasonably effective !
No! hardware and software experience are needed to program effectively.

Mahmood