Comment by viredfox

Normally we have a scope of what we want to do (ie. Let's redo the homepage and the login page). Then the product team group up and hash out the requirement, which is then sent to the developer. Although there are iterative changes in design, I actually don't know why the changes were made most of the time (they are not because of the implemented demo by the dev, the product team only starts seeing at the same time of QA)