Running Python from R

I am aware that there are multiple libraries for both languages (R/Python) to call modules from the other one. I am looking for a way to have the backend of my code running in python mainly because of .pyc and speed, and also the front end running in R so I can have a Shiny app. I couldn't find a way to make python machine for the backend. If anyone knows how to do it in R/Rstudio please respond.