I suspect that the problems on Scrum teams in my current organization supersede this one aspect, but wanted to focus the question more specifically to how Scrum can be done better than it is currently being done.
We are a new organization to Agile/Scrum and have many challenges. We are horizontally stratified to the point of sheer lunacy where nearly every aspect of software and technology has been provided through some external enterprise platform team that monopolizes an incredibly specific aspect of an overall software system (Eg. ESB team, Reporting team, DBA team, Scheduled Tasks Team, Business Events Notification, etc...)
Our project is a hub of sorts with an absurd number of external interfaces spiderwebbing into and out of our software that we are trying to deliver. We have many many many layers of abstraction from business and operations, to operation business analysts, to Product Owner, to business systems analysts that define detailed functional requirements in the form of user stories and acceptance criteria.
This project has a big budget so they formed off two scrum teams but to my extremely vocal objections the decision by the scrum master was to horizontally segregate the two scrum teams such that one scrum team deliver on user stories for stakeholders while the other scrum team delivers on more technical and interface stories in a digestable form for the other scrum team. My unheeded objections were that a user story should be a full vertical slice otherwise we harm our ability to be cross functional. The argument against mine is that even the simplest most atomized slice of business value could not be delivered in a two week sprint because of the obscene amount of external dependencies any one story calls for. Instead the second team works ahead of the user story team.
This is all failing miserably in practice, but despite all of this the bigger problem still is that our backlog grooming and sprint planning sessions take 8+ hours to complete.
Our scrum master insists that we cannot end the meeting until enough stories are ready for the next sprint, no matter what. Most of the stories just aren't ready in terms of requirements I feel to where the user story is clear and the acceptance criteria makes sense. I am constantly trying to stifle extended deep dive technical discussions that technical folks in the room insist on talking to death about but usually I just give up after a while and let them talk through whatever anxieties they have.
Originally I tried taking a hard stance in the meetings and calling the story Not Ready and moving back to Backlog, however I was being lectured from the frustrated Product Owner that we are failing to bring anything useful at all into the next sprint.
Next I tried to call for a return to Sprint Zero because we just aren't ready to work on anything yet. It is clear the Scrum Team needs more guidance on requirements and high level design, and being as I am responsible for system architecture, I agree that we are moving too fast for me to give the level of design detail that the technical folks feel they need to work on a story. I try to make up for this by being completely available for questions or concerns during the sprint but it doesn't ease the anxiety that the team feels about the impending public humiliation that comes when they are in standup and have to admit that they don't know what to do and that their story is at risk yet again. My call for Sprint Zero is unheeded by the Scrum Master who insists that we are not going to meet our strict regulatory deadlines of minimum scope if we "waste time" in Sprint Zero. It is a completely immutable position that he refuses to step down from.
So our Backlog grooming and Sprint planning has devolved into 8+ hr sessions where we essentially try our best to piece together requirements and design details for each story, and where discussions can go in excess of 45 minutes on each story.
This whole experience has me wondering if Scrum just doesn't scale to large projects in practice.
What else can I do as a technical architect to help pull the project out of this vicious death spiral it found itself in? How can I help the team get to a point where we can groom, slice and size a story in less than 10 minutes?