How to write android backend code for a React native UI

Question

I have a complete frontend ready in React Native (using Expo) and now I want to write the backend for it in Java. In my project directory, I see an android folder that resembles a project created using Android Studio (app → src → main → domain → MainActivity.java).

This file looks something like an android project but has many new overridden methods that I have never seen, so how do I go about writing the backend for the frontend of the application? Where could I find documentation regarding the same?

Answer 1

To write the backend in Java or any other stack, you have to write it as a separate project like any other application. However, you can modify the native android modules in react native. Here is a sample documentation for that.