JavaScript Cloud Native Development Cookbook

How it works...

First and foremost, zero-downtime deployment has to be treated as a first-class requirement and must be accounted for in the task roadmap and system design. If an enhancement is just adding a new optional field on an existing domain entity then a feature flag isn't required at all. If a field is just being removed, the order of deployment is important, from most dependent to least dependent. If an entirely new feature is being added, then access to the whole feature can be restricted. The most interesting scenarios are when a significant change is being made to an existing and popular feature. If the change is significant then it may be best to support two versions of the feature simultaneously, such as two versions of a page—in ...