The word toggle is used in everyday technology to describe a switch that can be changed between two positions: on and off. It is also used in computing and programming to refer to the ability to change a setting or mode from one state to another. For example, when you log into your gmail account, there are toggles for visibility and other settings that can be set. When you click on these toggles, they enable or disable the features and allow you to adjust your preferences.
Feature Toggles are an important part of any continuous development practice. They help mitigate the risk of regressions and give teams insight into how a new feature will be received by their users. In addition, they can act as circuit breakers in production to prevent a problem from impacting the entire user base.
In some cases, a toggle can be hardcoded directly into the application’s code. This method can be cumbersome and difficult to scale due to the need to modify the code every time a toggle is changed. In most cases this is avoided by storing the toggle configuration in an external data source such as a database or a dedicated centralized toggle management system.
For example, an ecommerce company may use experiment toggles to perform multivariate or A/B testing. The experiment toggle will consistently send a given cohort down either a A or B codepath and then compare the results of each. Once conclusive data is collected the experiment toggle will be removed and the winning codepath will go live for all users.
