In Kate Matsudaira's talk on Really Scaling a Rails Application, she makes an interesting distinction between V1 and V2 engineers. V1 engineers hack things together quickly. V2 engineers are slow and careful, writing documentation and unit tests. So I guess I'm a V2 engineer, and I used to get annoyed with the practice of hacking things together quickly. But seen in this light, I can see how V1 engineers have their place.