[paulbjensen]

I think it's ok to go without tests at the start of your project, but at some point you have to transition to using TDD, otherwise the ability to refactor the codebase or change existing features becomes difficult and time-consuming.

To give a rough idea, I spent ~ 2 1/2 months working on my app (Dashku.com) before I wrote a single test for it. Then when a company approached and asked to use it with a special requirement, I realised it needed tests in order to be deemed production-worthy. Now the app has tests (both unit and integration), and I'm now resuming adding features to the product.