For Agile projects, I often coach about the need for a QA (quality assurance) role in addition to just testers (or QC / quality control).
For me, QA answers the question “are we doing the right job?” and QC answers the question “are we doing the job right?”.
I see QA working with the Customer/Product Owner on coverage for acceptance and functional testing. A great QA person will be able to answer the architecture (“how do I - ?”) questions for the QC team as well as, like a great Business Analyst, be able to hold the domain model in their head. Could even be the same head (BA/QA)…