Web dev context here. Just from the top of my head: django-constace breaks storage format with no built-in no downtime transition, django-modeltranslations, want to add translations to a heavily used field and you are using a database without transactional ddl good luck with that, django-importexport used a savepoint per row making it useless if you want to import csvs with a few thousand rows, requests doesn't officialy declare thread safety, I could go on and on ...