android - How to quickly build 20+ versions of an app (with slight changes in each + different package)?

Question

We are developing an Android app that will target different markets (countries).

The scope of this question is to answer 2 things:

1. How to easily configure and switch a "global" parameter (e.g. the country which this "variant" of this app will target) within the app that will be used across the whole code base, e.g. a backend API endpoint. In other words, there are 20+ backend APIs depending on the variant being released.
2. How to easily build these 20+ different apps, changing the package name for each and taking into account the unique global parameter above while building each.

Answer 1

How to easily configure and switch a "global" parameter (e.g. the country which this "variant" of this app will target) within the app that will be used across the whole code base, e.g. a backend API endpoint. In other words, there are 20+ backend APIs depending on the variant being released.

Set up a product flavor per country. Use buildConfigField to add a field (or fields) to BuildConfig with the details of your backend endpoint.

How to easily build these 20+ different apps, changing the package name for each and taking into account the unique global parameter above while building each.

Run gradle assembleRelease to assemble all 20+ APKs. Or, run gradle assembleFlavorRelease to assemble the one APK with the flavor named flavor.