Flutter Architecture

Overview

Provides architectural guidance and best practices for building scalable Flutter applications using MVVM pattern, layered architecture, and recommended design patterns from the Flutter team.

Project Structure: Feature-First vs Layer-First

Choose the right project organization based on your app's complexity and team size.

Feature-First (Recommended for teams)

Organize code by business features:

lib/
├── features/
│   ├── auth/
│   │   ├── data/
│   │   ├── domain/
│   │   └── presentation/
│   ├── todos/
│   │   ├── data/
│   │   ├── domain/
│   │   └── presentation/
│   └── settings/
│       ├── data/
│       ├── domain/
│       └── presentation/
├── shared/
│   ├── core/
│   ├── data/
│   └── ui/
└── main.dart

When to use:

• Medium to large apps (10+ features)
• Team development (2+ developers)
• Frequently adding/removing features
• Complex business logic

Benefits:

• Features are self-contained units
• Easy to add/remove entire features
• Clear feature boundaries
• Reduced merge conflicts
• Teams work independently on features

See Feature-First Guide for complete implementation details.

Layer-First (Traditional)

Organize code by architectural layers:

lib/
├── data/
│   ├── repositories/
│   ├── services/
│   └── models/
├── domain/
│   ├── use-cases/
│   └── entities/
├── presentation/
│   ├── views/
│   └── viewmodels/
└── shared/

When to use:

• Small to medium apps
• Few features (<10)
• Solo developers or small teams
• Simple business logic

Benefits:

• Clear separation by layer
• Easy to find components by type
• Less nesting

Quick Start

Start with these core concepts:

1. Separation of concerns - Split app into UI and Data layers
2. MVVM pattern - Use Views, ViewModels, Repositories, and Services
3. Single source of truth - Repositories hold the authoritative data
4. Unidirectional data flow - State flows from data → ...