[menckenjr]

All due respect, it isn't really the same code base at all. RN assembles your app from a large list of components based on what your JSX file tells it needs to be imported. If you went and counted LOC you'd probably find that most of the lines of code (outside of the RN backbone) live in those modules. The common code you can share is your JSX.

[t1amat]

While technically correct it's not very meaningful a distinction in context. I'm not tasked with developing all the code required for every platform, I simply have to describe it once. Native platforms will all run off the exact same JavaScript bundle in a different, platform-specific shell. You wind up with a different bundle if you target the web.