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 is like having two identical restaurants — one is open (blue), and you're setting up the other (green) with the new menu.
Canary Release
A Canary Release is when you quietly send your new code to only a tiny slice of users first — like a test audience of 1%.
Feature Flag
A Feature Flag is an on/off switch for a feature in your app, controlled without redeploying. You ship the code but keep the feature hidden behind a flag.
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.