Toggle is a feature that allows you to easily control and monitor the behavior of an application. It’s useful for testing new features in a live environment, or for performing A/B testing and remote rollbacks. In some cases, the toggle can be turned on for a select group of users while the rest of the app continues to run without the new feature, allowing your engineering team to troubleshoot issues in real-world use.

Many organizations use toggles to deploy feature flags with the help of a centralized configuration system. This can be as simple as a static file or a simple preprocessor directive like #ifdef, all the way up to a full-blown Feature Flag management platform such as Kameleoon.

When working with toggles, it’s important to keep in mind the following best practices to ensure clarity for your users. For instance, toggles should be recognizable and consistent in their state with clear visual signifiers to communicate their current state. Using high contrast colors for state indication is recommended, and also taking into consideration societal and cultural context.

Toggle configurations should be easy to modify and re-configure. This will allow for rapid feedback cycles with the development and QA teams, and shortening the deployment cycle in general. Toggle configurations that cannot be re-configured at runtime are not ideal for production environments as they will require the re-deployment of an artifact to be updated and rolled back into the test environment. This can have a significant impact on the speed and quality of your validation process, affecting the overall speed of the feedback loop.