Performance Monitoring

Performance Monitoring Overview

Performance Monitoring lets you structure single-spa work so it stays readable, testable, and easy to scale. Instead of ad-hoc code, you follow a clear pattern that other developers can recognise immediately.

The key is to keep performance monitoring focused and predictable. Start from the minimal example here, then layer in only the complexity your feature actually needs.

import { registerApplication, start } from 'single-spa';

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});

start();

single-spa orchestrates multiple framework apps on one page through a root config.

Performance Monitoring Example

registerApplication({
  name: '@org/app',
  app: () => System.import('@org/app'),
  activeWhen: ['/app'],
});
start();

• Start from a minimal Performance Monitoring example and grow it only as needed.
• Keep configuration explicit so Performance Monitoring behaves the same in every environment.
• Name things clearly so teammates understand your Performance Monitoring at a glance.
• Add tests around Performance Monitoring early to lock in expected behaviour.

Single-SPA Cheatsheet

Core single-spa APIs related to performance monitoring.

How Performance Monitoring Works in Single-SPA

Performance Monitoring is part of how single-spa lets multiple applications — even in different frameworks — coexist on one page. A root config registers each app and controls when it is active.

single-spa orchestrates multiple framework apps on one page through a root config.

• A root config registers apps and calls start().
• Each app exports bootstrap, mount, and unmount lifecycles.
• activeWhen decides which routes each app owns.
• Import maps resolve each app's bundle at runtime.

Practical Guidance for Performance Monitoring

For reliable micro frontends, performance monitoring should isolate failures and keep shared state minimal. Let each team own its app end to end while agreeing on a few shared contracts.

Common Mistakes

• Skipping error handling and edge cases when wiring up performance monitoring.
• Leaving performance monitoring untested, so regressions slip into production.
• Over-engineering performance monitoring before you actually need the extra flexibility.
• Ignoring documentation, which makes performance monitoring hard for the next developer to change.

Key Takeaways

• Performance Monitoring is a core part of working effectively with single-spa.
• Start small and keep performance monitoring focused on a single responsibility.
• Apply consistent patterns so performance monitoring scales across your project.
• Test and document performance monitoring to keep it maintainable over time.