Feature Flags

What are feature flags?

Feature flags (also referred to as a feature toggle) is a technique to turn some functionality of your application off, via configuration, without deploying new code. This allows for better control and more experimentation over the full lifecycle of features.

Why use feature flags?

As feature development takes place server-side, they can be introduced simply as part of the product and engineering teams application development programme. As such feature flags are especially useful for teams using Agile and continuous delivery release programmes.

What are the benefits of using feature flags?

By taking an experimental approach and limiting exposure through rules, technical and performance risk can be greatly reduced. By first AB testing to a small segment of traffic, the team can determine the best version of a new feature or establish if the new feature represents an improvement. Once a feature has been tested and optimised, it can be rolled out as a ‘canary’ release. As such an informed decision can be established before full deployment.

In addition, as the changes in experience are all controlled entirely server-side, there is no risk of content flickering or need for page hiding techniques.

Examples of where feature flags can be used

• Payment options
• Checkout process
• Authentication method
• Site search algorithms

What are the considerations of using feature flags?

These are the same as Server-side testing in general. Coding and validation is conducted on the stack and will need to coordinate with the release programmes.

How can Webtrends Optimize help support release programmes

Through its REST API and Server-side testing platform, Webtrends Optimize can fully support feature testing. Once established, feature flags allow Marketers and non-engineers to test various features within products without the need for a code deployment.