Inside Flutter

Aggressive composability

Sublinear layout
Sublinear widget building
Linear reconciliation
Tree surgery
Constant-factor optimizations
Separation of the Element and RenderObject trees

Infinite scrolling

Viewport-aware layout
Building widgets on demand

API Ergonomics

Specializing APIs to match the developer’s mindset
Explicit arguments
Paving over pitfalls
Reporting error cases aggressively
Reactive paradigm
Interpolation

Conclusion