You can get pretty far with Flask. You'll need an ORM, so you'll likely chuck SQLAlchemy in. Then you'll want easier access to SQLAlchemy, sorta like, you know, django does it, so you pick up <a href="https://github.com/mitsuhiko/flask-sqlalchemy" rel="nofollow">https://github.com/mitsuhiko/flask-sqlalchemy</a>.<p>But you can't use pure SQLAlchemy models (easily), since this otherwise great extension for flask doesn't support it (<a href="https://github.com/mitsuhiko/flask-sqlalchemy/pull/250" rel="nofollow">https://github.com/mitsuhiko/flask-sqlalchemy/pull/250</a>, yes I'm in the thread).<p>You'll fork it or brew your own code to get declarative models working right. Kinda time consuming, but at least your models can be pulled in by <i>any</i> python code, and aren't tied down to a framework (That's what you were avoiding from the first place, wasn't it?)<p>Then you'll pick up WTForms (<a href="https://wtforms.readthedocs.io/en/latest/" rel="nofollow">https://wtforms.readthedocs.io/en/latest/</a>), another excellent library. And you'll miss having Django ORM's rich form and model-backed validation. So you'll try wtforms-alchemy, <a href="https://github.com/kvesteri/wtforms-alchemy" rel="nofollow">https://github.com/kvesteri/wtforms-alchemy</a>.<p>Then you'll begin to see why Django makes sense after using Flask for a while. Django pulls in all the essential stuff and supports it well.<p>And top of that, django's addons like django-extensions (<a href="https://django-extensions.readthedocs.io" rel="nofollow">https://django-extensions.readthedocs.io</a>), which gives you Werkzeug's debugger if you use ./manage.py runserver_plus. And ./manage.py shell_plus, which integrates with ptpython/ipython/bpython (<a href="https://django-extensions.readthedocs.io/en/latest/shell_plus.html" rel="nofollow">https://django-extensions.readthedocs.io/en/latest/shell_plu...</a>).<p>Django rest framework, DRF for short (<a href="http://www.django-rest-framework.org/" rel="nofollow">http://www.django-rest-framework.org/</a>), which is very mature at this stage, runs circles around Flask API. Flask API is inspired by DRF. You could also try <a href="https://flask-restful.readthedocs.io" rel="nofollow">https://flask-restful.readthedocs.io</a>, but after all that, you'll be missing that tight model support.<p>You'll <i>love</i> flask. The code is top tier and exemplary. The testsuites are a dream and are very clear. Documentation is awesome. It feels good to code in it. But django feels good to code in as well.<p>Django's ORM is very mature. It's easier than SQLAlchemy, and despite SQLAlchemy's purity, and documentation - even better than flask's - Django's ORM does the trick for pretty much anything, even foreign databases I've interacted with. Another thing, QuerySet's are a charm, a lot of django's addons like django-filters, django-rest-framework and django-tables2 are built on top of its versatility.<p>Another thing Flask community ends up having to clone from Django is django-debug-toolbar <a href="https://github.com/django-debug-toolbar/django-debug-toolbar" rel="nofollow">https://github.com/django-debug-toolbar/django-debug-toolbar</a>. See <a href="https://flask-debugtoolbar.readthedocs.io" rel="nofollow">https://flask-debugtoolbar.readthedocs.io</a>.<p>Again, I love flask, but when I realized that I'm just going to end up reinventing django with my flask app anyway, I started going with django on new projects. I haven't turned back, but still check out flask and sqlalchemy to see what's happening now and then.