Creating a Shared Component Library

In the modern development ecosystem—whether building web applications, mobile apps, or enterprise software—consistency, reusability, and scalability are vital. One of the most effective ways to achieve this across teams and projects is by creating a Shared Component Library.

A shared component library provides a single source of reusable UI components, business logic utilities, styles, and more, promoting code reuse, design consistency, and development efficiency. Whether you’re working with React, Angular, Vue, .NET, or other frameworks, the concept remains fundamentally the same.

In this article, we’ll explore what a shared component library is, its benefits, how to create one, and the best practices for long-term success.

What Is a Shared Component Library?

A shared component library is a centralized collection of modular, reusable components or utilities designed to be consumed across multiple projects or teams. These components can include:

UI components (buttons, inputs, modals)
Layouts and navigation elements
Form validators or input masks
Theme or styling systems
Utility functions
Icons and graphic assets
API clients or services

Instead of rewriting components in every project, developers import them from the shared library, ensuring standardization, maintainability, and reduction of duplicated effort.

Benefits of a Shared Component Library

Creating and maintaining a shared component library has numerous benefits:

1. Code Reusability

Reuse components across multiple applications or modules.
Avoid writing the same component multiple times.

2. Design Consistency

Ensure that UI elements follow a consistent design system (colors, typography, spacing).
Improve user experience across your application ecosystem.

3. Faster Development

Developers can focus on building features instead of reinventing the wheel.
Reduces time spent fixing inconsistencies or styling issues.

4. Centralized Updates

Fix a bug or enhance a component once and distribute it across all consuming apps.
Manage versions and rollbacks efficiently.

5. Better Collaboration Between Teams

Designers and developers align better by sharing and maintaining the same set of components.
Enhances team communication and reduces ambiguity.

When Should You Create One?

It’s worth investing in a shared component library if:

You maintain more than one application or frontend project.
Your team is large or spread across multiple development pods.
You want to enforce design guidelines or follow a design system.
You need rapid prototyping without recreating UI elements.

Common Use Cases

Internal enterprise dashboards
White-labeled web platforms
SaaS applications with modular UI
Product ecosystems with consistent UX
Shared design systems between web and mobile apps

Technology Stack Options

Depending on your tech stack, here are common choices for shared component libraries:

Framework	Tooling
React	Storybook, Rollup, TypeScript, Styled Components
Angular	Angular CLI, NX Workspace
Vue.js	Vue CLI, Vite
.NET	Razor Class Libraries
Flutter	Dart packages
iOS (Swift)	Swift Package Manager
Android (Kotlin)	Android Library Modules

Step-by-Step Guide: Creating a Shared Component Library (Web Example Using React + TypeScript)

Let’s walk through a simplified approach to creating a shared library for a web application using React and TypeScript.

Step 1: Set Up the Project

Use a monorepo tool like Nx, Lerna, or Turborepo, or create a standalone library using Vite or Rollup.

mkdir my-shared-library
cd my-shared-library
npm init -y
npm install react react-dom typescript rollup rollup-plugin-typescript2

Set up your tsconfig.json and rollup.config.js.

Step 2: Create Reusable Components

Create a folder structure:

/src
  /components
    /Button
      index.tsx
      styles.css
    /Input
      index.tsx
  /utils
    validateEmail.ts

Example Button component:

// src/components/Button/index.tsx
import React from 'react';
import './styles.css';

interface ButtonProps {
  label: string;
  onClick: () => void;
  variant?: 'primary' | 'secondary';
}

const Button: React.FC<ButtonProps> = ({ label, onClick, variant = 'primary' }) => {
  return (
    <button className={`btn ${variant}`} onClick={onClick}>
      {label}
    </button>
  );
};

export default Button;

Step 3: Add Exports

Create a central export file:

// src/index.ts
export { default as Button } from './components/Button';
export { default as Input } from './components/Input';
export { validateEmail } from './utils/validateEmail';

Step 4: Build the Library

Use Rollup to compile your code into a distributable format.

Example rollup.config.js:

import typescript from 'rollup-plugin-typescript2';

export default {
  input: 'src/index.ts',
  output: [
    { file: 'dist/index.js', format: 'cjs' },
    { file: 'dist/index.es.js', format: 'es' }
  ],
  plugins: [typescript()],
  external: ['react', 'react-dom'],
};

Run:

npx rollup -c

Step 5: Publish to npm or Git Repository

Add a meaningful package.json with a unique name.
Optionally publish to a private npm registry or GitHub Packages:

npm publish --access public

Or use Git submodules/private Git repos if you want tighter control.

Step 6: Consume the Library in Projects

In your applications:

npm install my-shared-library

import { Button, validateEmail } from 'my-shared-library';

<Button label="Click Me" onClick={() => alert('Clicked')} />

Best Practices

1. Follow Atomic Design Principles

Organize components by atomic hierarchy:

Atoms: Buttons, labels, inputs
Molecules: Input fields with labels
Organisms: Full forms or modals

This structure scales well and aligns with design systems.

2. Use Storybook for Documentation

Integrate Storybook to visually document components:

npx sb init

Storybook allows developers and designers to preview and test components in isolation, improving collaboration and usability.

3. Maintain Design Tokens

Use a central design token system (colors, spacing, font sizes) to enforce consistency:

:root {
  --color-primary: #0055ff;
  --spacing-sm: 8px;
  --spacing-md: 16px;
}

Tools like Style Dictionary or Figma Tokens can help sync design systems.

4. Versioning and Semantic Release

Use semantic versioning to manage updates:

1.0.1 = patch
1.1.0 = feature
2.0.0 = breaking change

Consider using semantic-release to automate version bumps and changelogs.

5. Write Unit and Snapshot Tests

Protect components with unit tests and visual regression tests:

Use Jest + React Testing Library
Use Chromatic for automated UI review

6. Keep It Framework Agnostic (Optional)

For utility or logic libraries, consider creating a framework-agnostic version (e.g., separate the logic from UI code).

7. Create Contribution Guidelines

If the library will be shared across teams:

Create a CONTRIBUTING.md
Define code style, testing rules, and branching models
Encourage documentation for new components

8. Use Typed Interfaces (TypeScript)

Provide type definitions for all components and utilities. This ensures better IDE support and developer experience.

9. Component Versioning and Deprecation

When deprecating components:

Clearly mark them in documentation
Provide upgrade paths or alternatives
Avoid silent removals

10. Optimize Bundle Size

Use tree-shakable exports and avoid large third-party dependencies inside the library. Monitor package size using tools like webpack-bundle-analyzer.

Challenges to Watch For

Challenge	Tip
Component bloat	Keep the library lean; use internal-only libraries if needed
Style conflicts	Use scoped CSS or CSS-in-JS libraries
Version mismatches	Automate versioning and maintain changelogs
Fragmented contributions	Set review standards and a governance model
Tight coupling to app logic	Keep components generic and configurable

Real-World Use Case: Multi-App Design System

Imagine a SaaS company with three products sharing a common design system. They use a shared component library to:

Enforce branding across web portals
Provide uniform login forms, dashboards, and modals
Share business logic (

like price calculators or permissions)

Streamline onboarding of developers

The shared library becomes a single source of truth—speeding up development and unifying user experience.