I'm new to TDD and have been reading the theory since applying it is more complicated than it sounds when you're learning by yourself.

As far as I know, the objective is to write test cases for each requirement and run the test so it fails (to prevent a false positive). Afterward, you should write the minimum amount of code that can pass the test and move to the next one.

That being said, is it true that you get a fast development, but what about the code itself? this theory makes me think you are not considering things like abstraction, delegation of responsibilities, design patterns, architecture and others since you're just writing "the minimum amount of code that can pass the test".

I know I'm probably wrong because if this were true, we'd have a lot of crappy developers with poor software architecture and documentation so I'm asking for a guide here, what's the relationship between TDD and Software Architecture/Design?