How to have a unified backlog with Scrum and Kanban teams

[Lars Böhnke]

Hey community! The Atlassian support was not able to help me but may you can, would be great!

We are trying to run one unified backlog with two Scrum teams, a data science Kanban team and a Kanban board for highest priority bugs (aka firefighting).

However, this is quite challenging. Let me explain the setup

Scrum: To Do > Ready > In Progress > In Review > Done

Firefighting and data science: To Do > Ready > Selected for Development > In Progress > In Review > Done

We are struggling with a few things, for example issues which are in progress or in review in the firefighting board show up in the Scrum backlog. The columns are configured correctly, I think it is because the issues are not part of a sprint thus not part of the Scrum board. But what is the correct way to handle those? I was looking for a way to exclude issues which are part of a given board but were not able to find something like that.

To identify different product areas we're using a custom field. However, the field is not inherited to sub-tasks which forces me to constantly re-selecting the field. When a filter with one product area is activated and I am creating an issue however, the field is set. Strange!

Also an issue with sub-tasks is the fact that the status is not inherited. So for example we have a user story which is 'Ready' and then during sprint planning the development team is creating subtasks. But now the subtasks have the to do status. Any idea how to work around that?