Dark Launch
ELI5 — The Vibe Check
A dark launch is deploying new code to production but keeping it invisible to users. The code is live, processing real traffic behind the scenes, but users see nothing different. It's like opening a restaurant kitchen and cooking full meals — but not serving them to anyone. You're testing that everything works at scale before flipping the switch.
Real Talk
Dark launching is a deployment technique where new functionality is deployed to production and exercises real traffic without exposing results to users. It validates performance, correctness, and scalability under production conditions. Combined with feature flags, dark launches enable teams to decouple deployment from release, reducing the risk of customer-facing issues.
When You'll Hear This
"We dark-launched the new search engine for a week before switching users over." / "Dark launch the API migration to validate performance before cutover."
Related Terms
Blue-Green Deployment
Blue-green deployment means running two identical production environments — Blue (current) and Green (new).
Canary Release
A canary release is like sending a canary into a coal mine — you deploy the new version to a tiny fraction of users first and watch closely.
Feature Flag
A feature flag is a toggle that lets you turn features on or off without deploying new code.
Progressive Delivery
Progressive Delivery means rolling out changes gradually instead of flipping a switch for everyone at once.
Shadow Traffic
Shadow traffic sends a copy of real production requests to a new service version without affecting users.