The Product Backlog is a dynamic concept that is never complete; especially, at the beginning of
the project. Trying to prepare a complete Product Backlog at the beginning of the project is a form
of upfront planning that doesn't suit Agile environments. The same goes for the architecture; it's
not designed upfront, because we don't know exactly what we're going to develop.All Sprints have the
same purpose of bringing value to the customer by creating a potentially releasable Increment.