The most painful thing about Android developing is api deprecation.
There is a old API which is bad, thus is deprecated in a newer API level, they introduced a new API for replacement. That's ok. I like using latest, better and non-deprecated API in my code.
But why this new API is deprecated again in several versions later??
And sadly, I'm using Samsung, so I'm on latest android version. However, my friend uses XiaoMi, which still running on Android 8. Now I have to cross 3 different API styles to do one single thing and it does not work, and make things worse, I don't know why.