A toggle is a button that has two states, on and off. It’s common in user interfaces (UIs) to use toggle buttons to control features such as notifications, keyboard shortcuts, and more. It’s also commonly used in coding to change the state of a variable between two states. A toggle can be triggered by a variety of conditions, including fitness tests from other code in the codebase, a setting set in feature management software, or a variable passed in via config file.
Feature toggles are useful when building new software because they enable developers to release code to users even while the team is still working on the feature. This supports agile development processes and enables teams to avoid a long testing and QA process that would typically be required under more traditional waterfall models.
Another useful application of feature toggles is enabling developers to deploy software in stages. By using a combination of feature flags and a canary release, engineers can test out new features on a small group of users before rolling them out to the entire audience. This helps them get feedback and optimize their features before they’re fully rolled out to the public.
However, it’s important to be careful about how a feature toggle is implemented, because there are some downsides to using this design pattern. For example, it can be hard for users to understand which side of a toggle is “on” since it doesn’t contain an on/off label. Additionally, if an engineer isn’t careful to name their toggles well, it can be difficult for other teams to find the right one when debugging issues.
It’s important to have a consistent process for naming and managing feature toggles in the codebase. This ensures that if there is an issue with one of the toggles, it can be quickly found and fixed. Additionally, it’s important to keep the number of feature toggles low and to prune them as soon as they’re no longer needed. The more idle toggles you have, the higher the maintenance burden on your team.
A good process for managing feature toggles involves four general categories: enabling, disabling, testing, and deploying. Each category has its own unique challenges, but they all require a similar set of processes to be successful. By following these best practices, you can create a consistent and effective approach to managing feature toggles. This will allow you to build great products that your users love.
