When my Scrum-style backlog grows up, it wants to be an FDD feature list … or is it the other way round?’ Why does Feature-Driven Development (FDD) organize its feature lists into a hierarchy? Why does FDD use a specific template to name the items in a feature list? While a Scrum-style backlog for a single team may never grow to more than a couple hundred items, backlogs serving multiple teams may easily do so and become hard to work with. We compare Scrum-style backlogs and FDD-style feature lists, and consider the relative merits of different ways of working with large backlogs.