Single-Spa Microfrontends

My journey with micro-frontends began when I was tasked with solving a critical challenge: how to enable multiple teams to work independently on different parts of our ad tech platform without stepping on each other's toes.

After researching various architectural patterns, I discovered the micro-frontend approach, which promised to bring the benefits of microservices to the frontend world. Among the different implementation options, Single-SPA stood out for its maturity and flexibility.

What particularly intrigued me about Single-SPA was its ability to:

• Integrate multiple frameworks (React, Angular, Vue) in a single application
• Enable independent deployment of frontend modules
• Support gradual migration from legacy to modern frameworks
• Provide a consistent user experience across different parts of the application

To validate this approach, I created a comprehensive proof of concept that demonstrated the integration of multiple frameworks within a single application. This became the Single-Spa-Microfrontends repository.

The POC included several key components:

• Root Config: The central hub that initializes and manages micro-apps based on routes
• React Navbar: A shared navigation component built with React
• Angular Legacy App: An older Angular v11 application, demonstrating migration paths
• Angular New App: A modern Angular v16 application, showing framework coexistence
• Shared Styleguide: Using TailwindCSS to maintain consistent look and feel

The most challenging aspect was orchestrating the loading and lifecycle management of each micro-frontend while ensuring they could communicate effectively without tight coupling.

I implemented a system where each micro-frontend ran on its own port during development:

• Root Config: 9000
• React Navbar: 9001
• Angular Legacy: 9002
• Angular New App: 9003
• Styleguide: 9004

Following the successful POC, I led the implementation of this architecture in our ad tech platform. This involved:

• Breaking down our monolithic frontend into domain-specific micro-frontends
• Establishing team boundaries and ownership for each micro-frontend
• Creating a shared component library to maintain UI consistency
• Setting up CI/CD pipelines for independent deployment
• Implementing cross-application state management and communication

The ad tech applications presented unique challenges due to their complex data visualization requirements and real-time data processing needs. We structured our micro-frontends around key business domains:

• Campaign Management
• Analytics Dashboard
• Audience Targeting
• Creative Studio
• Reporting Engine

Each domain was owned by a dedicated team, who could develop, test, and deploy their micro-frontend independently, significantly accelerating our development velocity.

The implementation of the micro-frontend architecture yielded significant benefits:

• Increased Development Velocity: Teams could work and deploy independently
• Improved Scalability: Both in terms of codebase and team organization
• Enhanced Resilience: Issues in one micro-frontend didn't affect others
• Flexible Technology Choices: Teams could select the best tools for their specific needs
• Gradual Migration Path: Legacy code could be replaced incrementally

However, the journey wasn't without challenges:

• Initial Setup Complexity: The learning curve and initial configuration were steep
• Bundle Size Management: Avoiding duplicate dependencies required careful planning
• Consistent User Experience: Maintaining UI consistency across teams required discipline
• Testing Strategy: End-to-end testing became more complex
• Performance Optimization: Loading multiple applications required careful optimization

Overall, the micro-frontend approach proved to be a game-changer for our organization, enabling us to scale our development efforts while maintaining a cohesive product experience.