Is it possible to setup a project which has code for both React Native(Mobile app) + React(web), having the code shred between platforms except for the UI part.
Have
You can try the repo that I tried to prepare:
https://mehmetkaplan.github.io/react-spa-jwt-authentication-boilerplate/
This has a step by step guideline that enables to share common logic between react and react-native applications.
It aims to differentiate only in the presentation layer. Other than that all logic is compiled to be shared between applications.
It also comes with facebook and google logins, database (mysql) integration, WebView task generation, etc.
And also it gives the fundamental know-how on "single page applications", "JWT (json web token) based security", etc..
Once read the README, you can simply clone the repo and set your environment (Database) and start developing business logic on top of the shared code structure and security baseline.