Metro - Scaling JavaScript Build Systems

Explore the architecture and ideas behind Metro, React Native's development server and bundler, in this JSConf EU 2018 talk. Dive into the challenges of scaling JavaScript build systems for large codebases, focusing on Metro's approach to achieving speed and reliability. Learn about file change monitoring, multi-layer caching, indirect dependency resolution, and various output formats optimized for both development and production environments on iOS and Android. Discover the journey to efficient bundling, including plain JS bundles, random access module bundles, and the require process for previously required and first-time modules. Gain insights into the Delta Bundler and how it contributes to Metro's performance in handling extensive React Native projects.

Intro
What is Metro?
Why are we building Metro?
Monitoring File changes
Multi-layer cache
Indirect dependency resolution
The Journey to a Bundle
Plain JS bundle
Random Access Module Bundles
Require process (previously required)
Require process (first time)
Delta Bundler