In my oppinion maybe it's too harsh to dismiss TDD. It's certainly good in some cases. But if you start using it everywhere everything will look like a nail whe

In my oppinion maybe it's too harsh to dismiss TDD. It's certainly good in some cases. But if you start using it everywhere everything will look like a nail when all you have is hammer. Clearly not everything is easily unit testable. What I like about unit testing that it's forcing you to separate irrelevant code and prevents you from writing spagetti code. In my personal oppinion you should test core functions as someone already said, which validates 90% code with 10% of time. And leave parts which can fail gracefully in case of a bug. It's not practical/impossible to test 100% of use cases of a big codebase. But you can test critical parts.