The Great Android Stack Reset: Mobile System Design History

Android, the last to arrive at the declarative UI party, took its time, until finally reaching a stable solution. Here's a rundown of the major changes in the Android System Design across the eras. I was away from Android for 7 years and came home to a totally strange place. This is my attempt to make sense of what happened while I was gone - how the stack reset four times (Activities -> MVP/RxJava -> Architecture Components -> Compose) and why each lurch happened. Written for interview prep but the history stands on its own.