Feature Flags
Feature Flags
- Definition: Feature flags are a software development technique that allows engineers to enable or disable features in a software application without having to deploy new code.
- Examples/References:
- LaunchDarkly: https://launchdarkly.com/
- Split: https://split.io/
Benefits of Feature Flags:
- Rapid experimentation: Feature flags allow engineers to quickly and easily test new features with a subset of users, without having to worry about breaking the production environment.
- Controlled rollouts: Feature flags can be used to control the rollout of new features to a wider audience, allowing engineers to monitor the impact of the feature and make adjustments as needed.
- Feature toggling: Feature flags can be used to toggle features on or off for specific users or groups of users, which can be useful for A/B testing, targeted promotions, or compliance purposes.
How Feature Flags Work:
- Feature flags are typically implemented using a configuration management system or a third-party service.
- When a feature flag is enabled, the code for that feature is included in the application. When a feature flag is disabled, the code for that feature is excluded from the application.
- Feature flags can be controlled through a user interface or an API, allowing engineers to easily manage and update feature flag settings.
Use Cases for Feature Flags:
- Testing new features: Feature flags can be used to test new features with a small group of users before releasing them to a wider audience.
- Controlled rollouts: Feature flags can be used to control the rollout of new features to a wider audience, allowing engineers to monitor the impact of the feature and make adjustments as needed.
- Feature toggling: Feature flags can be used to toggle features on or off for specific users or groups of users, which can be useful for A/B testing, targeted promotions, or compliance purposes.
- Kill switches: Feature flags can be used as kill switches to quickly disable features that are causing problems in production.
Feature Flag Tools and Products:
LaunchDarkly:
- Description: LaunchDarkly is a cloud-based feature flag platform that allows engineers to manage and control feature flags across their entire software stack.
- Link: https://launchdarkly.com/
Split:
- Description: Split is a feature flag platform that helps engineering teams build, test, and release new features faster and more safely.
- Link: https://split.io/
Flagsmith:
- Description: Flagsmith is an open-source feature flag platform that allows engineers to easily manage and control feature flags.
- Link: https://www.flagsmith.com/
Rollout:
- Description: Rollout is a feature flag platform that provides a simple and intuitive interface for managing feature flags.
- Link: https://rollout.io/
Optimizely:
- Description: Optimizely is a feature flag platform that helps engineering teams deliver personalized experiences to their users.
- Link: https://www.optimizely.com/
Additional Resources:
- Feature Flag Engineering Best Practices: https://martinfowler.com/articles/feature-flag-best-practices.html
- Feature Flags: A Practical Guide: https://www.oreilly.com/library/view/feature-flags-a-practical/9781098115137/
Some related terms to feature flags include:
- Feature toggles: Feature toggles are a specific type of feature flag that allows engineers to turn features on or off for specific users or groups of users.
- A/B testing: A/B testing is a method of comparing two versions of a feature to see which one performs better. Feature flags can be used to implement A/B tests by toggling different versions of the feature on for different users.
- Canary releases: A canary release is a technique for gradually rolling out a new version of a software application to a small group of users before releasing it to a wider audience. Feature flags can be used to implement canary releases by toggling the new version of the feature on for a small group of users.
- Dark launches: A dark launch is a technique for releasing a new feature to a small group of users without making it visible to the rest of the user base. Feature flags can be used to implement dark launches by toggling the new feature on for a small group of users and keeping it hidden from the rest of the user base.
- Kill switches: A kill switch is a mechanism for quickly disabling a feature or service in the event of a problem. Feature flags can be used to implement kill switches by toggling the feature off for all users.
Other related terms include:
- Continuous delivery: Continuous delivery is a software development practice in which changes are made to a system in small, frequent increments, and then tested and deployed automatically. Feature flags can be used to support continuous delivery by allowing engineers to quickly and easily test and deploy new features.
- DevOps: DevOps is a set of practices and tools that helps development and operations teams work together more effectively. Feature flags can be used to support DevOps by providing a way to safely and easily test and deploy new features.
- Microservices: Microservices is an architectural style in which a software application is composed of a collection of small, independent services. Feature flags can be used to support microservices by allowing engineers to independently develop and deploy new features.
These are just a few of the many related terms to feature flags.
Prerequisites
Before you can do feature flags, you need to have the following in place:
- A well-defined feature flagging strategy: This strategy should define how feature flags will be used within your organization, including the types of features that will be flagged, the process for creating and managing flags, and the criteria for when to use flags.
- A feature flagging tool or platform: This tool will provide the functionality you need to create, manage, and control feature flags. There are many different feature flagging tools available, so it is important to choose one that meets your specific needs.
- A process for managing feature flags: This process should define how feature flags will be created, reviewed, and approved. It should also define how flags will be monitored and maintained over time.
- A culture of experimentation and innovation: Feature flags are most effective when they are used to support a culture of experimentation and innovation. This means that teams should be encouraged to experiment with new features and ideas, and to use feature flags to safely and quickly test and deploy new features.
In addition to the above, you may also need to make some changes to your software development process and infrastructure in order to support feature flags. For example, you may need to implement a continuous delivery pipeline and/or adopt a microservices architecture.
Here are some specific things you can do to prepare for feature flags:
- Identify the features that you want to flag: Start by identifying the features that you want to be able to control with feature flags. These are typically features that are still under development, or that you want to be able to release to a subset of users before releasing them to everyone.
- Choose a feature flagging tool or platform: There are many different feature flagging tools available, so it is important to choose one that meets your specific needs. Some factors to consider include the number of features you need to flag, the level of control you need over flags, and the cost of the tool.
- Implement a process for managing feature flags: Once you have chosen a feature flagging tool, you need to implement a process for managing feature flags. This process should define how feature flags will be created, reviewed, and approved. It should also define how flags will be monitored and maintained over time.
- Educate your team about feature flags: It is important to educate your team about feature flags and how they can be used to support a culture of experimentation and innovation. This will help to ensure that feature flags are used effectively and responsibly.
What’s next?
After you have feature flags in place, there are a number of things you can do to get the most out of them:
- Use feature flags to support a culture of experimentation and innovation: Encourage your teams to experiment with new features and ideas, and to use feature flags to safely and quickly test and deploy new features.
- Use feature flags to control the rollout of new features: Use feature flags to control the rollout of new features to a wider audience. This allows you to monitor the impact of the feature and make adjustments as needed.
- Use feature flags for A/B testing: Use feature flags to run A/B tests to compare different versions of a feature. This can help you to determine which version of the feature is more effective.
- Use feature flags for targeted promotions: Use feature flags to target specific promotions or offers to specific users or groups of users.
- Use feature flags for compliance purposes: Use feature flags to disable features that are not compliant with regulations or company policies.
In addition to the above, you may also want to consider the following:
- Use feature flags to implement kill switches: Feature flags can be used to quickly disable features that are causing problems in production. This can help to minimize the impact of problems and protect your users.
- Use feature flags to support continuous delivery: Feature flags can be used to support continuous delivery by allowing you to quickly and easily test and deploy new features.
- Use feature flags to support microservices: Feature flags can be used to support microservices by allowing you to independently develop and deploy new features.
Overall, feature flags can be a powerful tool for increasing the agility and innovation of your software development process. By following the steps above, you can get the most out of feature flags and use them to improve the quality and performance of your software applications.