Release to some before you release to all.
Feature flags separate deploying code from releasing features. You can switch things on for a few customers, watch, and switch off instantly.
Internal
Your own team first.
A FEW %
A small group of real customers.
A QUARTER
Watch guardrails closely.
HALF
Confidence is growing.
EVERYONE
Then remove the flag.
Instant off switch
No emergency release needed if it goes wrong.
Real-world testing
Learn from real customers, with limited risk.
Deploy any time
Code ships continuously; features launch on purpose.
Clean up
Remove flags once rolled out, or they pile up.
Deploy anytime. Release on purpose.