Android applications should use background tasks when appropriate, and avoid doing everything on the app's main thread. In order to make the app both responsive for your users as well as a good citizen on the Android platform, take any blocking or long-running tasks off the main (UI) thread, and run them in the background instead. This includes tasks like decoding a bitmap, accessing storage, working on a machine learning (ML) model, or performing network requests.
Things to understand about background work include:
Understand Asynchronous work. This document explains asynchronous work, and helps you understand the difference between asynchronous and persistent work.
Persistent work is background work that remains scheduled through app restarts and system reboots.
Effective use of broadcasts. Much like the publish-subscribe design pattern, Android apps can send or receive broadcast messages from the Android system and other Android apps.
How to use the different techniques necessary to test asynchronous work versus testing persistent work.