I read a component checklist for C919 yesterday and it seems other than the main body, most if not all the internal pieces(including the engines) are outsourced

I read a component checklist for C919 yesterday and it seems other than the main body, most if not all the internal pieces(including the engines) are outsourced elsewhere. Boeing probably does something similar, in that it acts like more of a system designer and integrator, I recall its major software was also outsourced to some India company for its newest model.