You should have a plan to roll back releases that aren't fit for production.
In Kubernetes, rolling updates are the default strategy to release software.
In a nutshell, you deploy a newer version of your app and Kubernetes makes sure that the rollout happens without disrupting the live traffic.
However, even if you use techniques such as Rolling updates, there's still risk that your application doesn't work the way you expect it at the end of the deployment.
Perhaps it has a bug, or it wasn't configured correctly, and it keeps crashing.
When you introduce a change that breaks production, you should have a plan to roll back that change.
Kubernetes has a built-in mechanism for rollbacks.
Learn how it works in this article https://learnk8s.io/kubernetes-rollbacks/