In a user story mapping session, we should start by Identifying the different user types, then their goals or outcomes (represented on the map as activities), and the goals or outcomes of the company (represented on the map as versions or releases).
So for me it makes sense to try to deduct backbone tasks from user activities.
But in his book, Jeff Patton has an example (Everyday life) where he does the opposite, he first list all the tasks, then group them by higher goals or Activities.
So I am confused. From top goals to tasks, or from tasks to top goals ?
From top goals to tasks if you want to deliver fast.
Doing "As an HR manager I want to see turnover reports so I can better focus staff retention initiatives" first instead of starting with (e.g) a "Build CI/CD pipeline" task is the way to go.
That's because it eliminates waste and invites iterative problem solving: "At a minimum, what do we need for continuous integration/development so the HR manager can get her report?" is a great starting point. Go live on production with that, than beef up CI/CD as needed for the next story.