Bundle Size Optimization

This walks you through analyzing and shrinking your JavaScript and CSS bundles using tools like webpack-bundle-analyzer and Source Map Explorer. You'd reach for it when your builds are bloating, before deployments, or after adding dependencies that might have pulled in more than you bargained for. The skill focuses on code splitting, tree shaking, and identifying heavy libraries (the example calls out moment.js eating 67KB). It's most valuable when you're targeting mobile users or slow networks where every kilobyte counts. The reference guides cover the actual optimization techniques, though the quick start is more of a structure overview than working code.