Progressive delivery (blue-green, rolling updates, canaries, etc.) is a set of deployment practices that aim at rolling out new features gradually.
Release frequency keeps increasing and, with it, the need to get away from static environments like staging, integration, and other permanent setups. Dynamic environments based on pull requests are probably the best example of a need for a much higher level of dynamism. Kubernetes allows us to easily create whatever we need, and destroy what is not in use. There is no need for anything, especially not environments to be permanent, except for production. We can get far in that direction by combining GitOps practices and Argo CD in a way that each pull request (PR) creates a new environment that is destroyed when a PR is closed. By doing that, we can improve efficiency while, at the same time, reducing the costs.