[wvenable]

It varies pretty wildly but in my career a lot of code has lasted over 10 years and in some cases over 20. Also because code is sort infinitely copyable some code just keeps moving from product to product. Or some design moves from product to product. The longer you work in programming the more you have a set of tools that you can reach for over and over even if you're effectively writing it from scratch each time.

I think good code is vital to the software development process. It doesn't have to start out good but it should end good. Because you're going to be back at this code over and over. A little bit of effort up front can save you a lot of time in the long term.