As we all know, Ubuntu is an open, transparent community-based project, expressing its development (future goals, upcoming features, design processes, etc) in the open.
As a consequence, millions and millions of users from across the world can observe what, where, how, when related to Ubuntu, seeing process applicable to the professional-level design processes, too.
The experienced Ubuntu designer Ivanka Majic published a definitely interesting article about the design activity in and for Ubuntu, sharing a bundle of insights into the design activity.