apologies in advance if this is not the correct place to ask this question

do you mean app architecture? it is also my concern recently, have you found any good resources and forums. In my point of view, being in a project with good architecture could be a great start, then you could do a side project to build up from the beginning and ask a experienced mentor to review your code, then you can learn from that.

it’s not alone app architecture .. we can do several thing on that and there are many in market selling MVVM, MVP, VIPER to name few but that just gives you idea about how you should design your app.

yeah, I think I can feel you. However, back to your question, "Android system design" is something quite vague to me. From the way you explain above, were you talking about how to build a complete working app and then be able to understand the relationship between android components which are used?