Feature Toggles (Feature Flags)

Enables modifying system behavior and releasing features to specific user cohorts at runtime without deploying new code or restarting services.

STAFF ENGINEER TAKEAWAY: Decouples code deployment from feature release: ship code dark, enable for beta testers, then turn on globally with a toggle click.

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More Topics in 10. Deployment & DevOps

🔄CI/CD Continuous Integration & Delivery

Automates testing, linting, container building, and deployment of code updates, accelerating release velocity from months to minutes.

🔵🟢Blue-Green Deployment Strategy

Maintains two identical production environments (Blue and Green). One serves live traffic while the other is updated. Traffic is cut over instantly at the router.

🐤Canary Deployment Strategy

Rolls out new software to a tiny subset of users (e.g. 2%), monitors error rates and latency, and incrementally shifts remaining traffic if health checks pass.

🔄Rolling Deployment Strategy

Incrementally updates instances of an application by replacing old pods/servers with new ones one by one or in small batches.