Can you explain the internal architecture of the Flutter framework and how it works under the hood?

Flutter is a UI framework from Google for building cross-platform applications. Its internal architecture consists of several key layers:

1. Dart Framework — written in Dart, includes widgets, rendering, animations, and other high-level APIs.

2. Flutter Engine — written in C++, responsible for rendering using Skia, input handling, access to platform APIs, and graphics management.

3. Embedder — a layer that integrates the Flutter engine with a specific platform (Android, iOS, Windows, etc.), managing the application's lifecycle and interaction with the OS.

Under the hood, Flutter works as follows:

• The application is written in Dart and runs on its own Dart VM or is compiled into native code.
• The UI is built from widgets that describe the structure and behavior of the interface.
• When changes occur, Flutter creates a new widget tree, compares it with the previous one (diffing), and updates only the changed parts.
• Rendering is done through the Skia-based engine, which draws the interface directly onto the canvas, bypassing native platform components.

This ensures high performance and a consistent appearance across different platforms.