While all the fancy kids these days use containers in some form, some of us stick to Azure Web Apps for all sorts of reasons (good and not-so-good). And where all proper container-based platforms have mechanisms for seamless deployments of new versions, Azure Web Apps have Deployment Slots to achieve the same thing. In this talk, we'll take a lap around these Deployment Slots. Of course we'll touch upon the textbook case of swapping versions of workloads that handle web requests (Web Apps, HTTP-Trigger Functions), and we'll uncover some gotcha's there. For example: did you know that a long name for your Function app can break slot swapping? Yep, that's right. But it gets even more interesting when working with Azure Functions that respond to Service Bus messages. What options do we have to prevent the wrong version handling messages? And can you upgrade the .NET version or the Function Runtime version using deployment slots? For everyone interested in getting these and other questions answered: this talk is for you!