As QA tester, when do we need to do exploratory testing in Scrum?
Scrum does not have a recomandation for the timing of doing the exploratory testing.Scrum consider that testing, as any other activities like design..., is a part of the development effort needed to consider that the item/US is done. So exploratory tests should be done during all the development process of the US and they have specially more sense after passing all the planned tests with success, but they should be done certainly before considering the item DONE .