Advanced Flutter Flutter Interview Questions
4 questions
What are isolates in Dart and when do you need them?
An isolate is Dart's unit of concurrency — a separate memory heap and event loop running independently, with no shared mutable state — used to run CPU-heavy work in parallel without blocking the UI thread.
What are the main ways to build animations in Flutter?
Implicit animations (the `Animated*` widgets, like `AnimatedContainer`) animate a property change automatically with minimal code; explicit animations give full control via an `AnimationController` and `Tween`, for anything beyond a simple property tween.
What is CustomPainter used for?
CustomPainter lets you draw directly onto a canvas with low-level drawing primitives (paths, arcs, text, gradients) for visuals that no combination of standard widgets can produce — charts, custom shapes, signature pads.
What are platform channels and why are they needed?
Platform channels are Flutter's message-passing bridge to native platform code (Kotlin/Java on Android, Swift/Objective-C on iOS) — used whenever you need a platform API or native SDK that has no Dart equivalent.