Workflow engines have been around for some time. Basically, the idea is that you have a very high-level system where you can plug complex, independent components together. Microsoft's implementation of this has a very intuitive graphical interface and can be written either in the web browser or in a Visual Studio. When you cannot find a pre-built component that does what you need, you can call out to an HTTP endpoint, allowing the workflow to seamlessly integrate with Azure Functions or, indeed, with another cloud provider.
Azure functions are what is known as serverless; this isn't because they are magical and run without any hardware, but simply that you, as the developer, need not care what they are running on. They are intended to be small units of functionality—think of a single method in C#—...
