Why use remember?It retains a value at its composition position across recompositions. Leaving composition or changing a supplied key resets it. Remembering an ordinary mutable object does not make that object observable. State.
Why does modifier order matter?Order defines nesting of layout, drawing and input behavior. Padding before a background is outside its painted area; reversing them paints the padding too. The click target also depends on where clickable appears. Modifiers.
When can derivedStateOf be useful?When a derived result changes less frequently than observed inputs, such as a scroll-to-top flag derived from an item index. It has overhead; ordinary string concatenation usually needs no derivedStateOf. derivedStateOf.
What is the difference between LaunchedEffect and rememberCoroutineScope?LaunchedEffect runs a coroutine on entry and restarts it when its keys change. A remembered scope supports work started by callbacks. Both are composition-bound; neither automatically stops work whenever the Activity stops. Effects.