What design patterns are used in Flutter?

Design patterns are divided into three fundamental groups:

StatefulWidget is more of a beginner way to show how to pass state in a flutter application. For production level applications, there is the BLOC pattern which is another way of managing state inside a flutter application. There are other ways, but the BLOC pattern is highly recommended by the Flutter team.23 Haz 2019

Flutter Design Patterns: 21 — Visitor.

Provider pattern is recommended by the flutter team at Google . They also covered it at Google I/O 2019 in Pragmatic State Management in Flutter. Some other patterns such as BLoC Architecture use provider pattern internally. But the provider pattern is far easier to learn and has much less boilerplate code.