A toggle is a switch with two positions, on or off. In a user experience design sense, toggles are used to enable or disable features or settings on a website or application. It is often a clickable element on a page, and its click action can be triggered by the users or by other events in the system. For example, a toggle can be used to switch between light and dark themes on a web application, or to allow users to change the color of text in a form.
A key benefit of using feature toggles is their ability to help your engineering team experiment with code changes in production without risking your whole product release. This allows them to test new features in real-world use by a small group of select users, and then remotely roll back the feature for further testing by other users.
For instance, a team might want to test two different suggestion algorithms on their e-commerce configurator, in order to see which one performs better at getting customers to complete their orders. To do this, they add an experiment toggle to the production configuration tool, which splits users into two cohorts by applying a modulo to their request for the configurator. If the toggle is toggled to ON, all users see the suggested algorithm with the modulo of 1, while if the toggle is toggled to OFF, users see the recommended algorithm with the modulo of 2. After three weeks, the team has conclusive data and decides to remove the experiment toggle, and to implement the preferred algorithm across their entire user base.
Toggles are also useful for supporting agile development processes by allowing you to hide and release new features on the fly, without having to build the code out in a separate branch before integrating it into trunk code, as would be required under more traditional waterfall development models. This helps reduce the time you spend debugging code and shortens your deployment cycles.
Finally, they can act as circuit breakers in your application by allowing you to keep key functionality running during periods of high latency or other performance issues. This can be a crucial way to avoid disrupting your user base while you work on solving problems that may be causing them frustration.
When designing your toggles, make sure that they are clearly labelled so that anyone on the team can understand their purpose at a glance. This will prevent confusion or miscommunication if the toggle is changed to an ON state by another team member. Also, it is best to avoid having too many toggles in a production environment since they can negatively impact the overall performance of your database by driving up read queries.
It is recommended that you use a feature flag management platform such as Kameleon to store all of your toggles in a centralized repository, making them easy for your engineering team to manage and remove as needed.
