First and foremost: this : https://flask-sqlalchemy.palletsprojects.com/en/2.x/ This is the old Flask website built in flask. Some patterns are outdated. But still pretty nice to gloss over with a cup of tea and some buiscuits. 🙂 https://github.com/pallets/flask-website/tree/master/flask_website scoped_session(sessionmaker()) or plain sessionmaker() ? Well, the recommended pattern is to use scoped_session as it is considered thread safe. […]