You can see that there's a common backend ("configerator") that a lot of other systems ("sitevars", "gatekeeper", ...) build on top of.
Just imagine that these systems have been further developed over the last decade :)
In general, there's 'configuration change at runtime' systems that the deployed code usually has access to and that can switch things on and off in very short time (or slowly roll it out). Most of these are coupled with a variety of health checks.
https://research.facebook.com/publications/holistic-configur...
You can see that there's a common backend ("configerator") that a lot of other systems ("sitevars", "gatekeeper", ...) build on top of.
Just imagine that these systems have been further developed over the last decade :)
In general, there's 'configuration change at runtime' systems that the deployed code usually has access to and that can switch things on and off in very short time (or slowly roll it out). Most of these are coupled with a variety of health checks.