What is the best approach in Azure App Service to test a new app version without affecting end users?

Deployment slots in Azure App Service allow you to deploy different versions of your application to separate environments (slots) within the same App Service plan. You can deploy a new app version to a staging slot, test it thoroughly, and then swap it with the production slot with zero downtime. This ensures that end users are not affected during testing or deployment. Scaling out instances increases capacity for the current version, not for testing a new one. Redeploying the existing app directly replaces the live version, causing downtime or issues for users. Auto Heal helps recover from application failures, but doesn't facilitate testing new versions.