If you are interested in a standard but fully functional Python webapp with the newly released Wolfram Engine (Engine for short henceforth) behind a REST service, take a look at this proof of concept.
It's the minimal example of a Python based web app using the Wolfram Engine via the Wolfram client library for Python. It highlights a few features which would be more complex to develop with more classic engines:
The Engine is just a single box for a whole lot of technology you can assemble yourself in different ways but Wolfram makes it simply easy to prototype things. That said, there are of course drawbacks and concerns as well but this would requires a book on its own (scalability, cost, security, continuous integration and whatnot). Aside from the grand enterprise architectural concerns the following came up during development of this POC:
All in all, the Engine is potentially a magical solution for all sorts of applications (prototypes). The amount of (computational) intelligence you get for free is astonishing. At the same time, we are still far away from production-ready and scalable technology. I would describe this as prototyping paradise.