App Development Tools and Technologies Practice Test

A feature flag is a conditional toggle that lets you turn features on or off at runtime without releasing a new app build. In mobile releases, this means you can ship the code for a feature but keep it disabled, then enable it for all users or just a subset when you're ready. This supports gradual rollouts, canary releases, and A/B testing, while also allowing a quick rollback if something goes wrong—without forcing users to update the app. It decouples deployment from release, so you can push updates with unfinished features and enable them later, manage risk, and iterate based on real user data. Typically implemented via remote configuration that the app fetches, with caching and sensible fallbacks to maintain a smooth user experience. This isn’t primarily a security measure, a UI design pattern, or only about server-side routing; it’s a runtime switch to control feature availability across users and environments.