Flickr does something similar with their feature rollouts, instead of branching code they define "flags and flippers" to implement it alongside the existing cod

Flickr does something similar with their feature rollouts, instead of branching code they define "flags and flippers" to implement it alongside the existing code. This lets them gradually test it at scale (expose the new feature to x% of their users and slowly grow x). More details on their dev blog: http://code.flickr.com/blog/2009/12/02/flipping-out/ http://code.flickr.com/blog/2009/12/02/flipping-out/