The Risks and Benefits of Using Toggles in Software Development

A toggle is a switch that can be set in two positions, on and off. It’s used to change settings or alternate between multiple functions, for example switching between the video chat window and the map view in a multi-layered browser interface. A physical toggle switch can also be used, such as the one on a keyboard that turns the caps lock or num lock function on and off. In software development, a toggle is a way to enable or disable features in a release.

Toggles are a powerful tool in a developer’s arsenal but they do have some drawbacks and risks to be aware of. A significant risk is that using a toggle in a release may result in code which has many if-else statements and violates clean coding principles. This is especially true for a system that uses a toggle as part of its experimentation process and the toggle needs to be flipped in a testing environment on a frequent basis.

Another major risk is that a toggle system which is managed via static files can be very cumbersome at scale. Modifying the toggle configuration via these static files can be difficult and ensuring consistency across a fleet of servers can be challenging. In order to solve this challenge many organizations move toggle configuration out of static files and into a centralized store, typically an existing application DB.

This often accompanies a build out of some form of admin UI that allows systems operators, testers and product managers to view and modify the Features Flags and their toggle configuration. This can help reduce the friction associated with flipping a toggle in a testing environment, while also reducing the likelihood of unexpected regressions from changes to the toggle configuration in production.