Aem Frontend Build Pipeline

AEM Frontend Build Pipeline

Purpose

Implement modern frontend build pipelines for AEM including webpack/Vite configuration, client library generation, CSS/JS optimization, and integration with AEM's ui.frontend module architecture.

When to Use (Triggers)

• User mentions "frontend build," "webpack," "client libraries," or "ui.frontend"
• References to npm, CSS compilation (SASS/LESS), or JavaScript bundling
• Questions about clientlib generation, code splitting, or asset optimization
• Requests involving SPA frameworks (React/Angular/Vue) with AEM integration
• Discussion of frontend development workflow, hot reload, or proxy configuration

Core Capabilities

• Configure webpack/Vite for AEM clientlib generation via aem-clientlib-generator
• Implement CSS preprocessor pipelines (SASS/LESS) with PostCSS optimization
• Set up JavaScript bundling with tree-shaking and code splitting
• Configure frontend proxy development workflow with AEM backend
• Integrate SPA frameworks with AEM SPA Editor SDK

Domain Knowledge Required

Technical Foundation

• Module bundlers (webpack 5, Vite, Rollup) and their configuration
• CSS preprocessors (SASS, LESS) and PostCSS plugin ecosystem
• JavaScript module systems (ESM, CommonJS) and code splitting strategies
• Node.js/npm project management and dependency resolution

AEM-Specific Context

• AEM Client Library (clientlib) structure (js.txt, css.txt, categories)
• aem-clientlib-generator npm package for automated clientlib creation
• AEM Archetype ui.frontend module structure and build integration
• SPA Editor SDK (React, Angular) and its build requirements
• Component-scoped styles vs. global theme clientlibs
• Client library dependencies and embed patterns

Implementation Approach

Step 1: Project Structure

Set up the frontend module within AEM project.

• Initialize ui.frontend module following AEM Archetype patterns
• Configure package.json with build scripts (dev, prod, watch)
• Set up source directory structure (components, themes, utilities)
• Define clientlib output categories aligned with page structure

Step 2: Build Configuration

Configure the bundler for AEM-compatible output.

• Set up webpack/Vite with appropriate entry points per clientlib category
• Configure aem-clientlib-generator for automated clientlib creation
• Set up CSS extraction and optimization (MiniCssExtractPlugin / Vite CSS)
• Configure asset handling (fonts, images, SVGs) with correct paths

Step 3: Development Workflow

Enable rapid frontend iteration.

• Configure webpack-dev-server / Vite dev server with AEM proxy
• Set up hot module replacement (HMR) for CSS and JS changes
• Configure source maps for debugging in AEM context
• Implement BrowserSync or similar for multi-device testing

Step 4: Optimization

Apply production optimizations to build output.

• Configure tree-shaking for unused code elimination
• Implement code splitting for route-based or component-based chunks
• Set up CSS optimization (purging, minification, autoprefixer)
• Configure long-term caching with content hashing

Step 5: CI/CD Integration

Integrate frontend build into deployment pipeline.

• Configure Maven build to trigger npm build via frontend-maven-plugin
• Set up Node.js version management in CI environment
• Implement build caching for faster CI runs
• Configure environment-specific builds (dev, stage, prod)

Quality Checklist

• Production build outputs optimized, minified bundles
• Source maps available for debugging but not shipped to CDN
• Client library categories correctly mapped to page regions
• No JavaScript errors in browser console on any page template
• CSS doesn't conflict between components (scoped or namespaced)
• Build time under 60 seconds for full production build
• Hot reload works for both CSS and JS changes in development
• Bundle size within budget (< 200KB JS gzipped for initial load)

Related Skills

• aem-component-development (frontend of components)
• aem-caching-strategy (clientlib caching with fingerprinting)
• aem-performance-tuning-profiling (frontend performance measurement)

Example Use Cases

1. Design System Integration: Implement a shared design system (Storybook-based) that compiles into AEM clientlibs, enabling component development outside AEM with seamless integration via the build pipeline.
2. SPA Migration: Convert traditional AEM site to React SPA using AEM SPA Editor SDK, configuring webpack for both SPA Editor-compatible builds and standalone development mode with mock data.
3. Micro-Frontend Architecture: Implement Module Federation (webpack 5) for independently deployable frontend features within AEM, enabling different teams to deploy frontend changes without full site rebuild.

Notes

• frontend-maven-plugin downloads and manages Node.js — don't require global Node installation for builds
• Client library categories determine loading order — plan categories carefully to avoid blocking rendering
• AEM Cloud Service supports the same frontend build patterns as on-premise
• Vite is gaining adoption for AEM frontend builds due to faster dev server and simpler configuration