@beberlei is now introducing how generic and reusable feature flags (with Symfony) can be at #SymfonyCon with examples of payment system.

He referred to

["Flipping out" by Flickr (2009)](http://code.flickr.net/2009/12/02/flipping-out) and also
["Feature toggle" by Marting Fowler (2010)](http://martinfowler.com/bliki/FeatureToggle.html)
["Feature Toggles in Symfony" by labs @ Qandidate.com](http://labs.qandidate.com/blog/2014/09/04/feature-toggles-in-symfony2/)