What you do when you start a new project? Usually, we begin with database design, then we prepare a migration system, user registration, and all different stuff that distracts us from doing what is most important - business logic. With the clean architecture, we can learn how to start a project in another way and this will be one of two main topics of my talk. The second one will be about new features in Python. You probably heard about typings, mypy, and dataclasses, but I will show you how they can be used in real life project that can be developed over many years in production lifecycle. There will be no ““hello world”” app, no copy & paste of documentation, only practical knowledge learned through many years of practice.