I love Scrum on both philosophical and practical levels; but I'm not sure that I am sold on the idea of User Stories being an optimal boundary for units of work.
User Stories are great, and use of user stories as units of work places what I would agree is an appropriate emphasis on wholly integrated value to the customer. However, I also see value in defining work along other (non-feature) boundaries, especially for the sake of enforcing a definition of done.
Stated another way, I see value in continuous integration, even outside of the boundary of user stories. I think most Dev teams would agree that they see value in that. Does this mean we need another "Definition" here to promote continuous integration prior to story completion? Or is it feasible for our unit of work to (possibly, sometimes) be something other than a user story?
The only downside I see of allowing non-user facing stories is that we could get stuck in the weeds of tasks that do not add real value to the user. The alternative, from what I have seen, is larger units of work that cost more to integrate.
Every team is different, but I would rather err on the side of more predictable units of work and guard against non-valuable work through grooming and review.
Has anyone else encountered this need for a tradeoff?