JavaScript Modules and Bundlers

Mon, 23 Mar 2026 00:00:00 +0000

The goal here is to understand JavaScript module systems (IIFE, CommonJS, ESModules), how modern bundlers sit on top of them, and which build types to use for business apps and component libraries.

Module systems describe how code is organized and imported/exported at the language level. Bundlers and build tools consume those modules and produce optimized outputs for different environments (browser, Node, CDN, etc.).

Part 1 — Module Systems

IIFE (Immediately Invoked Function Expression)

IIFEs are the classic pattern to create a private scope and avoid polluting window, often combined with a single global namespace like App.

Modules on Osmar Petry

JavaScript Modules and Bundlers

Part 1 — Module Systems

IIFE (Immediately Invoked Function Expression)