But when your browser requests this one CSS file, it’s still being executed
through a dynamic Symfony route. For production, that’s way too slow. And
depending on your setup, it may not even be working in the prod environment.
The secret? The assetic:dump console command. Run it in the prod
php app/console assetic:dump --env=prod
This wrote a physical file to the web/css directory. And when we refresh,
the web server loads this file instead of going through Symfony.
When we deploy our application, this command will be part of our deploy process.