The process of design requires refinement.  As development proceeds, the requirements may change depending multiple factors which may include design choices or part availability.

I plan on using JAVA as my programming language on android devices.  If it becomes necessary for performance reasons, I will move to programming in C.  These are the only real choices for development on android devices.  You can run emulators or virtual machines but they usually take a significant performance hit on low power devices.

For the programmer side of the design, I plan on programming in C for most of the design, and assembly language for performance critical pieces.  I will avoid assembly language altogether if possible.

Refinement may require these choices to change, for instance any code written for IOS products must be in objective C.  There may not be a C compiler for the microcontroller I decide on.