Feature toggling is a technique used to enable or disable certain behaviors of the system (typically at runtime). This makes release management much easier (e.g., Dark Launching, Canary Releases, Blue-Greed Deploy, A/B testing, etc.). Many leading companies (such as Facebook, DropBox, and Google) use these techniques to gradually release and test new features to a small set of their users before releasing to everyone. This technique can also be used as an alternative to maintaining multiple feature branches, and thus can reduce the cost of long-lived branches. There are commercial and open-source frameworks available in different technologies to help implement feature toggling. Among those, FF4J is a very good Java-based, open-source framework that addresses most of the feature toggle aspects and works very well with mircroservices/Spring Boot particularly, with very easy integration. This session will demonstrate feature toggling using FF4J framework for Spring/SpringBoot applications.