The processing step.
WHY A BUILD EXISTS
Source code uses features, syntax and structure that benefit from processing before delivery.
WHAT PROCESSING INVOLVES
Combining modules into files Converting newer syntax for older browsers Compiling frameworks and type systems Processing stylesheets Optimising images Removing unused code Minifying output Adding version identifiers to filenames
WHY VERSIONED FILENAMES
So assets can be cached indefinitely, and a change produces a new address.
WHAT A DEVELOPMENT SERVER PROVIDES
Serving the application locally Updating the browser when files change Source maps, so errors point at your code
WHY SOURCE MAPS MATTER
Without them, an error points at minified output, which is unreadable.
WHAT TO GENERATE FOR PRODUCTION
Source maps, uploaded to your error reporting rather than served publicly.
WHAT TO CHECK IN ANY BUILD
Output size Build time That output actually works, which differs from development
WHAT TO KEEP
The configuration, understood by more than one person.