Everybody works on master, with feature flags! Yes! Also, if you have proper dependency injection for testing and developer sandboxes, that's the right layer t

Everybody works on master, with feature flags! Yes! Also, if you have proper dependency injection for testing and developer sandboxes, that's the right layer to vary your back end. If statements only needed when setting up the dependency environment. In PHP we do this with polymorphic classes; in Haskell with type classes and the ReaderT monad.