A toggle is a switch that can be either on or off. It is a simple yet very useful tool to have when designing an interface. When designing with toggles, it is important to consider how a user will interpret them. In order to reduce confusion it is recommended that designers use clear and direct labels with visual cues to convey the state of a toggle. In addition it is important to evaluate societal and cultural context when using color for toggle states as some colors can have very different meanings in certain cultures.

Savvy teams view their Feature Toggles as inventory that comes with a carrying cost and seek to minimize the amount of time that a toggle spends flipped On. To accomplish this most teams manage their Feature Toggle configuration in some type of centralized location, often an existing application DB. Then when a toggle is no longer needed it can be modified via this central location. This can be more efficient than having to hardcode changes directly into the codebase. It also allows teams to take advantage of features like automatic re-configuration when testing and debugging.

Another way to leverage the power of a toggle is to expose it as an endpoint that can be called at runtime to re-configure an instance of a service. This is commonly done when performing multivariate or A/B tests. It can greatly speed up the test cycle and allow teams to quickly exercise a variety of different path scenarios. It should be noted that when exposing an endpoint that allows for runtime re-configuration of a toggle it’s recommended to use a robust and automated testing infrastructure. Otherwise the overhead of having to restart a test process or re-deploy an artifact into a test environment can be significant.