For anything larger than that though, Flask has always turned into a giant headache for me. As soon as I ever start to try and organize the project better because it's become too large for a single file, all shit hits the fan. Supposedly this has gotten slightly better with 0.7's Blueprints, but I've yet to see it. Circular imports and Flask's global variables bite me in the ass on a regular basis. I also have come to really miss tons of features that Django offered, like URLconfs. The decorator technique works great when you can count the number of URLs that your app has on two hands. Beyond that, ack/grepping my project to find where anything lives isn't my idea of maintainable. With Django I can very cleanly trace through the whole request/response cycle in my head and by looking at the code paths.