Flutter Development Concepts and Methods

Problem What are the core concepts and methods you should know in Flutter development?

Be ready to discuss

• The widget tree: StatelessWidget versus StatefulWidget, widgets as immutable configuration, and the distinction between the widget tree, element tree, and render tree.
• Build and rebuild: what build() is responsible for, how setState() marks an element dirty and triggers a rebuild, and why keeping build() cheap and side-effect free matters.
• State lifecycle: initState, didChangeDependencies, didUpdateWidget, dispose — and what belongs in each (subscriptions in initState, teardown in dispose).
• State management options: setState for local state versus Provider, Riverpod, or Bloc for shared/app state, and the reasoning for choosing one.
• Layout algorithm: constraints flow down, sizes flow up, parent sets position — and the common layout widgets (Row, Column, Stack, Expanded, ListView) plus debugging unbounded-constraint errors.
• Compilation and tooling: Dart JIT in development enabling hot reload versus AOT compilation to native ARM for release, and hot reload versus hot restart (preserved state versus reset state).
• Performance: keys and why they matter for list identity, const constructors, ListView.builder for lazy rendering, and avoiding rebuilds of expensive subtrees.