If you truly want no magic and barebones "on the metal" code, go with Flask. You'll have every choice down to the way you serialize your objects into views, mo

If you truly want no magic and barebones "on the metal" code, go with Flask. You'll have every choice down to the way you serialize your objects into views, models, and every aspect of the database. You can write everything yourself with no or minimal dependencies, or pull in the most popular packages as you see fit (SQLAlchemy, Marshmallow, Jinja, etc.). Django will provide some (useful) magic, but nowhere near as much as Rails. If the site evolves, I really recommend transitioning to Django for it's ecosystem. In either case, I recommend sticking with plug-and-play auth. (Disclaimer: I'm an engineer at a startup whose backend is 90% Python, mostly Django.)