The trouble is, larger apps are logical extensions of smaller apps in Flask. I find it rather pleasant to use Flask to build large RESTful APIs, but I don't find there to be any interesting challenges or insights that would make it worthwhile to produce an article relating the experience. I'm afraid it's the same way for many people I know who are using Flask to build large APIs at their companies - the process is so predictably boring that I doubt any of them have even considered writing about it.