Writing web-apps

I was speaking with Avinash of SupportBee today. He shared an interesting way of looking at webapps. What if we looked at webapps as one blob that holds all the business-logic, interfaced with a persistent store (db) and a http web-interface. This isn't MVC, where the business logic gets invariably sprinkled over models, views and controllers. "Think of it like as writing normal ruby/python object oriented code, that simply plugs into a storage and http providing interface". This needs in-memory model-like objects (apparently, Active Model in Rails does this) without the saving part, and some lightweight http interface (flask?).