Micro Frontend Architecture Explained for Angular Developers

Micro Frontend architecture splits a large frontend into:

Smaller applications - Each handles a business domain
Independent codebases - Separate repositories
Domain-focused systems - Clear ownership boundaries

Each micro frontend:

Owns a business domain - Products, Checkout, Admin, etc.
Has its own repository - Independent version control
Can be deployed independently - No coordination needed

To users, everything still feels like one application.

The Core Concept

Traditional Monolithic Frontend

code

┌─────────────────────────────────┐
│   Single Angular Application   │
│                                 │
│  ┌──────┐ ┌──────┐ ┌──────┐    │
│  │ Prod │ │ Cart │ │ User │    │
│  └──────┘ └──────┘ └──────┘    │
│                                 │
│  One codebase, one deployment   │
└─────────────────────────────────┘

Micro Frontend Architecture

code

┌──────────────┐  ┌──────────────┐  ┌──────────────┐
│   Products   │  │   Checkout   │  │    Admin     │
│   (Remote)   │  │   (Remote)   │  │   (Remote)   │
└──────┬───────┘  └──────┬───────┘  └──────┬───────┘
       │                 │                 │
       └─────────────────┼─────────────────┘
                         │
              ┌──────────▼──────────┐
              │   Host Application   │
              │   (Shell/Orchestrator)│
              └─────────────────────┘

Key Principles

1. Domain Ownership

Each micro frontend owns a complete business domain:

Products App: Product catalog, search, filters
Checkout App: Cart, payment, order processing
Admin App: User management, analytics, settings

2. Independent Development

Separate repositories
Separate teams
Separate development cycles
No shared codebase conflicts

3. Independent Deployment

Each app deploys on its own schedule
No coordination required
Rollback affects only one app
Faster release cycles

4. Runtime Integration

Apps integrate at runtime (not build time)
Host application loads remote modules
Users see one seamless application

How It Works

Step 1: Host Application

The Host (or Shell) application:

Provides the application shell
Handles routing
Loads remote modules dynamically
Manages shared layout

Step 2: Remote Applications

Remote applications:

Are complete Angular applications
Expose modules to the Host
Run independently
Can be accessed standalone

Step 3: Runtime Integration

When a user navigates:

Host detects route change
Host loads appropriate remote module
Remote module renders in Host's container
User sees seamless experience

Real-World Example

E-Commerce Platform

Products Micro Frontend:

Team: Product Catalog Team
Repository: products-app
Deploys: Daily
Owns: Product pages, search, filters

Checkout Micro Frontend:

Team: Payment Team
Repository: checkout-app
Deploys: Weekly (more cautious)
Owns: Cart, payment, order confirmation

Admin Micro Frontend:

Team: Admin Team
Repository: admin-app
Deploys: As needed
Owns: User management, analytics

Host Application:

Team: Platform Team
Repository: host-app
Deploys: Rarely (infrastructure only)
Owns: Routing, layout, navigation

Benefits

For Teams

✅ No merge conflicts
✅ Independent release cycles
✅ Clear ownership boundaries
✅ Faster development

For Business

✅ Faster feature delivery
✅ Lower deployment risk
✅ Better scalability
✅ Technology flexibility

For Users

✅ Seamless experience
✅ No difference from monolithic app
✅ Better performance (lazy loading)
✅ More reliable (isolated failures)

The Technical Foundation

Micro Frontends in Angular use Module Federation (Webpack 5 feature) to enable:

Runtime code sharing
Dynamic module loading
Shared dependency management

The next module compares this with monolithic approaches.

Module 2: Micro Frontend Architecture Explained for Angular Developers