Immutable infrastructure is a DevOps approach that emphasizes the creation of disposable resources instead of modifying existing ones1. This approach helps to achieve stability, consistency, and predictability in IT operations by reducing the risk of configuration drift and eliminating stateful components1.

One way to implement immutable infrastructure is to use a blue-green deployment strategy, which runs two live environments for configuration changes2. The blue environment is the current production environment, while the green environment is the new version of the application or service. When the green environment is ready, the traffic is switched from blue to green, and the blue environment is destroyed or kept as a backup2. This way, there is no need to update or patch the existing infrastructure, but rather replace it with a new one.

References:

1: Immutable Infrastructure, Architecture, and its benefits

2: Introduction to Immutable Infrastructure – BMC Software | Blogs