Autoload Mapping for modules I'm trying to better understand how Drupal 8 autoloading for classes is automatically mapped to the src directory in modules.

Basically, I'd like to know how the system knows to look in the modules/module_name/srс directory when searching for classes.

I can't seem to find any details on how it's done through the composer.json files or the autoload_psr4.php files. Perhaps I'm looking in the wrong place?
Drupal 8 follows PSR 4 autoloading standard which is implemented by composer autoloader.

While some Drupal namespaces are registered statically in composer.json and core/composer.json other namespaces are processed dynamically (see DrupalKernel::classLoaderAddMultiplePsr4).

PSR-4 namespaces and autoloading in Drupal 8