Module Federation Performance

Performance sits at the heart of performance in Module Federation. This guide walks through the concept step by step, with examples, a cheatsheet, and common mistakes to avoid.

Performance Overview

Performance is a building block you will reach for often in Module Federation. It keeps related logic together and makes your intent obvious to reviewers and future maintainers.

When you learn performance properly, you avoid the guesswork that leads to bugs and rework. The example below shows the shape you will use in most real Module Federation projects.

const { ModuleFederationPlugin } = require('webpack').container;

module.exports = {
  plugins: [
    new ModuleFederationPlugin({
      name: 'shell',
      remotes: { catalog: 'catalog@http://localhost:3001/remoteEntry.js' },
      exposes: {},
      shared: { react: { singleton: true }, 'react-dom': { singleton: true } },
    }),
  ],
};

ModuleFederationPlugin configures which modules an app exposes, consumes, and shares.

Performance Example

new ModuleFederationPlugin({
  name: 'app',
  filename: 'remoteEntry.js',
  exposes: { './Widget': './src/Widget' },
  remotes: { other: 'other@http://host/remoteEntry.js' },
  shared: { react: { singleton: true } },
});

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

Module Federation Cheatsheet

Key Module Federation settings related to performance.

Option	Example	Purpose
name	`name: 'shell'`	Unique container name
filename	`filename: 'remoteEntry.js'`	Remote entry manifest
exposes	`exposes: { './X': './src/X' }`	Modules a remote shares
remotes	`remotes: { app: 'app@url' }`	Remotes a host consumes
shared	`shared: { react: { singleton: true } }`	Deduplicate libraries
lazy load	`import('remote/Module')`	Load remotes on demand
Suspense	`<Suspense fallback={...}>`	Handle async loading

How Performance Works in Module Federation

Performance builds on Module Federation's ability to load code from another independently built and deployed application at runtime. Each app can be a host, a remote, or both.

ModuleFederationPlugin configures which modules an app exposes, consumes, and shares.

Remotes expose modules through a remoteEntry.js manifest.
Hosts declare remotes and import exposed modules dynamically.
Shared dependencies are deduplicated, ideally as singletons.
Each micro frontend builds and deploys on its own schedule.

Practical Guidance for Performance

In production, performance needs careful version management and graceful failure handling. Align shared dependency versions and always render a fallback when a remote cannot load.

Concern	Recommendation
Shared versions	Use singletons with requiredVersion
Runtime errors	Wrap remotes in error boundaries and fallbacks
Deployment	Resolve remotes from a runtime manifest
Performance	Lazy-load remotes and cache remoteEntry.js

Common Mistakes

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

Key Takeaways

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

Pro Tip

Pair performance with automated tests from day one. It is far cheaper to catch Module Federation regressions in CI than in production.