Who hasn’t been scared when deploying a new feature to a website? Sometimes we feel that we will break everything, and the stress level is just not something we want to experience ever again. That's why the deployment slots feature of Azure App Services is such a nice experience. With deployment slots, you can deploy to a safe slot in the same conditions as your production environment. You can test in isolation, without risking breaking something. Then you can gradually route some of the traffic to the new features, for example to perform A/B testing. When you are satisfied with the results, you can simply switch the whole traffic to the new site. But don't fret, if something goes wrong, the old, safe site is just one mouse click away.