I define WP_PLUGIN_URL in wp-config.php to different domain from my WP_SITEURL.
define('WP_SITEURL', 'http://' . $_SERVER['SERVER_NAME']);
define('WP_HOME', 'http://' . $_SERVER['SERVER_NAME']);
define('WP_CONTENT_URL', 'http://static.example.com/wp-content');
define('WP_PLUGIN_URL', 'http://static.example.com/wp-content/plugins');The minified CSS and javascript didn't work for files in plugins and themes directory
