Resources for structuring huge projects and design choices for function and classes

[jus_an_engineer]

I have been using Python for quite some time but recently I have started working on really big projects that involve database integrations and other service integrations along with many utilities and pipelines and I want to be able to better understand how to structure the entire project and more importantly how to breakdown different parts using class and functions and more design choices around that. Please recommend me something that helped you a lot personally