5 feature flag best practices
Feature flags are a powerful tool for high-performing product and engineering teams.
They give product managers more control over releases and make the rollout and testing of new functionality easier.
However, without adopting best practices, organizations can quickly end up creating more chaos than clarity.
In this article, we'll explore some of the key feature flag best practices that can help you optimize the management of your flags, reduce the risk of errors or complications, and, ultimately, let you deliver better software.
Feature flags: the basics
Feature flags (also called feature toggles, feature switches, and feature flippers) are if/else logic code snippets that are used to enable or disable features.
They are the foundation of feature management, allowing development and product teams to separate deployment from release and roll out features with confidence.
Developers and product managers primarily use feature flags to:
- Release or roll back features with ease.
- Release features gradually to specific user groups.
- Roll out feature variations to a subset of users.
- Run experiments on new features with greater control and precision.
- Gather quantitative user feedback.
We wrote an extensive guide to feature flags that covers some of the key use cases and benefits of this powerful tool. If you’re looking for more information about feature flags, we recommend starting there.
The impact of poor feature flag management
It’s easy to start using feature flags without considering how they’ll be managed. If you’re only dealing with a handful of flags on the engineering team, then stringent processes may not feel necessary.
However, feature flag management can quickly get out of hand as organizations scale, and more flags get introduced to the code.
Poor feature flag management can result in:
- Accumulating technical debt: too much technical debt can lead to increased maintenance costs, reduced system performance, and increased risk of software failures. Moreover, outdated and unarchived feature flags may end up conflicting with new ones teams create later, causing additional issues.
- Unnecessarily complex code: code may be harder to read, debug, and maintain, and can slow down your development process.
- Confusion and inconsistency: inconsistent feature flag practices can affect a team’s ability to collaborate and can slow down release cycles.
- Reluctance towards feature flagging: the resulting consequences of poor feature flag management often leads teams to miss out on the benefits gained from implementing feature flagging.
Therefore, following feature flag management best practices is essential to reap the benefits of feature management. Without them, you’ll be left with more work than when you began.
5 feature flag best practices
Implementing feature flagging effectively requires following a set of best practices to avoid potential pitfalls. Here are five best practices for feature flagging to get started.
1. Determine the type of flag you want to create
How you manage a flag will depend on what type of flag it is and what it is being used for. Therefore, it’s important to determine the type of flag you want to create before getting started. Types of flags include:
- Short-term flags: these are created for a specific short-term purpose, such as a release flag, and should be removed immediately after use is over.
- Permanent flags: these are created for a long-term purpose, such as a killswitch, and need to be managed more carefully.
- Experiment flags: these are created for feature experimentation through feature flags.
The type of feature flag you choose will determine its behavior and the impact it has on your software development process.
2. Standardize the creation process
The standardization of the creation process can make it easier to locate what you’re looking for and speed up internal processes. Therefore, every feature flag that fulfills the same purpose or function should be created in exactly the same way.
This includes identifying and outlining processes for naming conventions, tagging, deletion of old flags, and anything else that may be repeated in the creation process.
You’ll also want to consider role-based access rights and who will be able to create and edit flags in the system you’re using. Doing so can minimize the risk of deleterious effects from unauthorized access.
Naming a feature flag
Effective feature flag names can help you quickly understand what each flag controls and how it relates to the overall system, reducing the risk of confusion and mistakes. Here are three tips to follow when creating your flags.
1. Be clear and descriptive: Choose a name that clearly indicates what the flag controls. Refrain from using vague or ambiguous names that can cause confusion.
2. Use a consistent naming convention: Standardize the naming process, and ensure consistency in naming conventions is maintained across teams.
3. Document naming convention rules: Create an internal document that clearly outlines naming convention rules to easily onboard new team members and improve workflows.
3. Plan the reach of the flag
Make feature flag planning a part of feature design from the beginning. You’ll want to determine what part of your code is controlled by the feature flag so that it doesn’t live on a critical path in your app.
The reach of a feature flag should also be minimized so that it triggers a specific action and that action only. By limiting a feature flag to a specific action, you can prevent the chance of accidentally causing another unintended action.
4. Review flags and clean up at regular intervals
Perhaps one of the most important (and often overlooked) best practices for feature flag management is reviewing and cleaning up flags at regular intervals.
When unmanaged, feature flags can quickly lead to technical debt. Knowing when to remove flags and old code containing irrelevant flags can make all the difference in avoiding technical debt.
An easy way to do this is to schedule monthly feature flag reviews where any old or unutilized flags are pruned from the code.
5. Make flags backward compatible
Making flags backward compatible means that when a new version of a software application is released with a new feature flag, the flag is designed to be compatible with previous versions of the application.
This ensures that if users do not update to the latest version, the application will still function as intended without any negative impact or loss of functionality.
It also provides a safety net for engineers, who can roll back to a previous version of the application if there are any issues with the new version of the feature flag.
In the case of a rollback, the fallback should be seamless, both technically and for end users.
By adopting best practices for feature flagging, teams can minimize the risk of errors, accelerate continuous delivery, and improve the overall quality of their software.
These best practices include creating clear and descriptive flag names, standardizing the creation process, making flags backward compatible.
With these best practices in mind, product and engineering teams can optimize their feature flagging practices and deliver high-quality software that meets customer needs and drives business success.
To learn more about feature flags, refer to our guide on feature flagging.