When it comes to building microfrontends, performance is crucial for delivering an excellent user experience. However, these architectures introduce specific challenges that can impact load time and runtime performance. In this article, we'll explore the key performance considerations and strategies for optimization in microfrontend applications.

Increased Initial Load Time

One of the most significant performance challenges in microfrontends is increased initial load time. When using independent microfrontends, users may experience:

  • Multiple application bundles loading sequentially
  • Redundant framework code across applications
  • Multiple initialization cycles
  • Increased total JavaScript processing time

The good news is that the performance impact varies significantly based on the implementation approach.

Implementation Approach Performance Impact

Here's a breakdown of the initial load time and main performance concerns for different implementation approaches:

| Implementation Approach | Initial Load Time | Main Performance Concerns |

| --- | --- | --- |

| Route-based distribution | Low (one app at a time) | Route transition delays |

| iFrame integration | Medium | Multiple framework instances, memory usage |

| Framework-based (Mooa/Single-SPA) | Medium-High | Framework overhead, coordination costs |

| Web Components | Low-Medium | Browser support, polyfill size |

| Component composition | Low | Build complexity, dependency sharing |

Managing Dependencies

How dependencies are managed significantly impacts performance in microfrontend architectures. There are two primary approaches:

  • Standard LazyLoad: Angular's built-in lazy loading
  • Build-time integration: Separate development, combined at build time
  • Post-build integration: Separate build, combined at runtime
  • Application independence: Fully separate applications

Communication Overhead

Microfrontends require communication between applications, which introduces performance overhead. The implementation approach determines the communication mechanism and associated performance costs:

| Communication Method | Performance Impact | Use Case | Implementation |

| --- | --- | --- | --- |

| Custom events | Low | Simple data | window.addEventListener('mooa.routing.navigate', ...) |

| Iframe postMessage | Medium | Isolated apps | iframeEl.contentWindow.postMessage() |

| Shared state | Low-High | Complex data | Framework-specific (Redux, etc.) |

| Direct function calls | Lowest | Framework-based | Single-SPA/Mooa lifecycle hooks |

Lifecycle Management

Microfrontend applications can create memory management challenges, especially when multiple frameworks coexist or applications aren't properly unmounted:

  • Multiple framework instances: Can significantly increase memory usage
  • Zombie event listeners: May cause memory leaks if not properly cleaned up
  • Retained DOM elements: Can persist even after application unmounting

The lifecycle management in frameworks like Mooa helps address these issues by enforcing proper mounting and unmounting.

Performance Strategies

To optimize app user experience, consider the following strategies:

  • Preloading critical applications: Load shell application first, then progressively load features
  • Efficient application switching: Keep previously loaded applications in memory, implement proper unmounting to prevent memory leaks
  • Minimize inter-application communication overhead: Use events for lightweight communication
  • Shared vendor bundles: Extract common dependencies into shared bundles

By implementing these strategies and understanding the performance implications of microfrontend architectures, you can deliver an excellent user experience and optimize your app's performance.