There is a great site out there that offers up a checklist you should conduct before launching your symfony project to production, check out the following link:

http://symfony-check.org/

One cool note that is definitely worth mentioning is the “Display an unavailable message during maintenance operations” check. Basically you can configure a setting in your settings.yml file which will redirect a user to an ‘unavailable’ page during a ‘symfony cc’. This will avoid the problem where some users may get white pages during your publish process, and will also ensure that incomplete template caches are no longer a problem.