What is Feature Flag?
Turkish: Feature Flag
A feature flag controls who sees a feature and when it is enabled, without requiring a new code deployment, separating release decisions from deploys.
What is a Feature Flag?
A feature flag uses configuration to turn a piece of application behavior on or off. It separates deployment from release: code can be shipped to production while the feature is visible only to a user, team, region, plan, or traffic percentage.
How Does It Work?
At a decision point, the application reads the flag value. If it is enabled, the new path runs; otherwise the old path remains active. The value may come from an environment variable, database, remote configuration service, or dedicated feature management tool.
In gradual rollout, a feature may first be enabled for the internal team, then a small customer group, and then a percentage of production traffic. If a problem appears, the flag can act as a kill switch. This pattern supports smaller, more frequent releases in CI/CD pipelines.
Business Use
Feature flags are used for beta features, paid-plan entitlements, regional launches, temporary maintenance modes, and A/B testing. Product teams can test different experiences from the same codebase without exposing every user at once.
Flags should not remain forever by accident. Expired flags create branching code paths, expand the test matrix, and make it harder to know which behavior a user actually saw.
Related Terms
A/B testing measures two design, copy, or feature variants with real user traffic to learn which option performs better.
Canary DeploymentCanary deployment sends a small share of traffic to a new release first, then expands rollout only if metrics stay healthy.
CI/CD (Continuous Integration / Continuous Delivery)CI/CD makes software releases repeatable by moving code changes through automated build, test, and deployment pipelines.