Feature Flag
A toggle that enables or disables a feature in production without deploying new code.
Definition
Feature flags (also called feature toggles) are conditional code blocks that let you control which users see new features. They decouple deployment from release: you can deploy code to production with features hidden behind flags, then gradually enable them for specific user segments. This enables canary releases, A/B testing, percentage-based rollouts, and instant rollback if something breaks.
Feature flag platforms like LaunchDarkly, Statsig, and Flipt provide SDKs, targeting rules, and analytics. Even simple boolean flags in a config file count as feature flags.
Why it matters for founders
Feature flags reduce deployment risk dramatically. Instead of hoping a big release works, you can test with 1% of users first. They also enable product experimentation: test new features with specific cohorts and measure impact before committing.
Example
Airbnb uses feature flags extensively. When they redesigned their search experience, they rolled it out to 5% of users, measured conversion impact, iterated, expanded to 25%, then 100%. If metrics dropped, they could disable the flag instantly without a code rollback.
How Foundra helps
Foundra's iterative validation approach aligns with feature flag philosophy: test small, measure, and scale what works before committing fully.
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Related terms
A/B Testing
Comparing two versions of something to determine which performs better based on data.
Minimum Viable Product (MVP)
The simplest version of your product that lets you test your core hypothesis with real users.
Iteration
The process of making incremental improvements based on user feedback and data.
Product Roadmap Planning
The strategic process of prioritizing features and defining the sequence of what to build and when.