How we ship code faster and safer with feature flags

This post introduces the concept and implementation of feature flags at GitHub. It details how feature flags are used to reduce deployment risk by allowing features to be enabled/disabled quickly without full rollbacks. It also explains how feature flags facilitate incremental development of new features by allowing work on small batches and avoiding long-lived feature branches. The post outlines different shipping strategies (individual actors, staff shipping, early access, percentage of actors, dark shipping) and discusses what entities can be flagged (users, organizations, repositories, etc.). Finally, it touches on the runtime costs and technical debt associated with feature flags, including the development of a script to automate the cleanup of dead code and old tests.