CODIUM

If you're interested in Python, I would say that Django is the best choice for a framework written in Python because it comes with lots of ready-to-use features. PostgreSQL is also a great choice for database too. It has many extensions and many advantages when using with Django (ArrayField, and etc.). Our company have been using this stack very long time and it works great!

If the application is simple such as less endpoint or simple logic, I'd suggest Flask. But what you're building is quite a large system that contains many logics and a lot of models. So I'd suggest you with Django and Django REST framework. Django ORM is also one of the best ORM in the world as well.