What are some best practices for using feature toggles without negatively impacting user experience?

1 Choose the right type of toggle

Feature toggles can be classified into four types, based on their lifespan and purpose: release, experiment, operational, and permission toggles. Release toggles are used to hide unfinished or risky features until they are ready for launch. Experiment toggles are used to run A/B tests or multivariate tests on different user segments. Operational toggles are used to control the availability or behavior of features based on external factors, such as load, time, or location. Permission toggles are used to grant or restrict access to features based on user roles, preferences, or subscriptions. Choosing the right type of toggle for each feature can help you optimize your development, testing, and deployment processes, as well as avoid unnecessary complexity or confusion for users.

2 Design for toggleability

Not every feature can or should be toggled. Some features may be too complex, interdependent, or critical to be switched on or off at runtime. Therefore, you need to design your features with toggleability in mind, by following some principles, such as modularity, cohesion, loose coupling, and abstraction. Modularity means that your features should be divided into small and independent units that can be easily isolated or integrated. Cohesion means that your features should have a clear and single responsibility that matches their scope and name. Loose coupling means that your features should have minimal dependencies or interactions with other features or components. Abstraction means that your features should hide their implementation details and expose only their interfaces or contracts. By following these principles, you can make your features more manageable, testable, and toggleable.

3 Use a robust toggle framework

Implementing and maintaining feature toggles can be challenging, especially if you have many features and users. You need to ensure that your toggles are reliable, secure, scalable, and consistent across different platforms and environments. You also need to monitor and measure the impact of your toggles on user behavior and app performance. To achieve these goals, you need to use a robust toggle framework that can handle the complexity and variability of your feature toggles. A toggle framework is a software tool that provides features and functions to create, configure, control, and evaluate feature toggles. Some examples of toggle frameworks for mobile apps are Firebase Remote Config, LaunchDarkly, Optimizely, and Apptimize. By using a toggle framework, you can simplify your toggle management and improve your toggle quality.

4 Communicate and educate users

Feature toggles can create different user experiences for different user groups, depending on how they are enabled or disabled. This can lead to confusion, frustration, or dissatisfaction for some users, who may not understand why they see or don't see certain features, or why their experience changes over time. To avoid these negative outcomes, you need to communicate and educate your users about your feature toggles. You can use various methods, such as in-app messages, notifications, tooltips, FAQs, or feedback forms, to inform your users about the purpose, benefits, and expectations of your feature toggles. You can also provide your users with options to opt-in or opt-out of your feature toggles, or to customize their preferences or settings. By communicating and educating your users, you can increase their awareness, engagement, and trust in your feature toggles.

5 Clean up and remove obsolete toggles

Feature toggles are not meant to be permanent. They are meant to be temporary and transitional, until the features they control are fully developed, tested, deployed, and validated. Keeping obsolete toggles in your codebase can cause technical debt, code rot, performance degradation, and security risks. Therefore, you need to clean up and remove your toggles once they are no longer needed or useful. You can use some strategies, such as setting expiration dates, documenting toggle owners, tracking toggle usage, and automating toggle removal, to ensure that your toggles are timely and properly disposed of. By cleaning up and removing your toggles, you can maintain your code quality, app performance, and user experience.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?