Feature Flagging 101: What Are Feature Flags?

What are feature flags?‍

They’re more than just a buzzword, we promise. A feature flag, also known as a feature toggle, is a software development technique that allows developers to turn certain features on or off within an application, website or system without having to deploy new code. Feature flags can be used to activate or deactivate specific features, control the visibility of certain features, or change the behavior of a feature based on different conditions, such as user conditions and who the feature is being shown to. 

…Okay, so what do feature flags actually look like? 

Feature flags can take many different forms in code depending on the programming language and the feature flag management tool being used. Here is a simple example of what feature flags might look like in code using a basic if/else statement:

In this example, the featureEnabled() function would check whether the "newFeature" flag is enabled. If it is, the code for the new feature would be executed. If not, the code for the old feature would be executed instead. The specific implementation of the featureEnabled() function would depend on the feature flag management tool being used.

Another example might be using a feature flag to control the display of a UI element:

In this case, the featureEnabled() function would check whether the "newButton" flag is enabled. If it is, the new button would be displayed. If not, the old button would be displayed instead. Again, the specific implementation of the featureEnabled() function would depend on the feature flag management tool being used.

Next up: What are feature flags used for?

Dev teams use feature flags for a variety of reasons. (Our own users prove this true everyday - they're constantly teaching us new use cases for our own product!) Take a look at some of the cool things they’re using DevCycle’s feature flags for here 👀  

One of the most common reasons dev teams use feature flags is to test new features before they are fully released to users. By turning a feature flag on, developers can test new features in a controlled environment and get feedback from a small group of users before releasing the feature to everyone. This reduces the risks associated with releasing new features that may not be fully tested or.have a negative impact upon user experience.

Feature flags are also used to control the release of new features to users. Instead of releasing a new feature to all users at once, feature flags allow developers to gradually release the feature to small groups of users to test how the feature performs in the real world. This allows developers to identify and fix any issues before releasing the feature to everyone.

In addition, feature flags can be used to enable or disable specific features based on user preferences, device types, or other conditions. For example, a feature flag can be used to enable a feature only for users who have opted in to a beta testing program or disable a feature on a specific device type that is known to have compatibility issues.

How do feature flags improve the software development process?

….In other words, what’s in it for you? 

Feature flags offer several benefits to dev teams. To name a few:

Faster Release Cycles

With feature flags, developers can release new features to users faster and more efficiently than ever before. By testing new features in a controlled environment and releasing them to small groups of users, developers can identify and fix issues before releasing the feature to everyone. This means that you can roll out new features quickly and with confidence, without sacrificing the quality of your product. ‍

Reduced Risk

‍Feature flags are like a safety net for your software development process. With feature flags, developers can test and release new features in a controlled manner, which reduces the risk of bugs or other issues that can affect the user experience. It's like having a trial run before the big reveal, so you can catch any problems before they become a bigger issue. Plus, you can feel more confident in releasing new features to your users without worrying about the negative impacts because you can quickly turn them off

Improved User Experience

‍With feature flags, developers can enable or disable specific features based on user preferences, device types, or other conditions. This means that you can provide a personalized user experience that meets the unique needs of each user to make sure they’re getting the best possible experience with your product.

Greater Flexibility

With feature flags, developers can turn features on or off at any time, which means they can quickly respond to changes in user needs or market conditions. This means that you can make adjustments to features as needed, without being tied down to a rigid release process. With feature flags, you can be nimble, flexible, and respond to user feedback in real time. 

Wrapping up (for now)...

Feature flags help dev teams deliver new features to users faster, more efficiently and with fewer risks. By allowing developers to test and release new features in a controlled manner, feature flags reduce the risks associated with releasing new features and speed up the release cycle. In addition, feature flags provide greater flexibility in software development processes and allow developers to provide a personalized user experience that meets the needs of each user.

That’s all for our first post in our Feature Flagging 101 Blog Series, but stay tuned for more content later this week! Up next, we’ll cover general feature flagging use cases.

(If you want to test out feature flags for yourself as you follow along in the blog series, you can do so at app.devcycle.com!)