Who are developing these changes? Is it the same people that design them? I.e UX people? Does it boil down to stories in sprints for someone to develop? Someh

Who are developing these changes? Is it the same people that design them? I.e UX people? Does it boil down to stories in sprints for someone to develop? Somehow I don't think this is the result of patches or pull requests by developers in a traditional sense.