⟩ Explain me which online communities have you managed in the past and what were your responsibilities?
An obvious question, but one that throws up almost everything you need to know about their skill set. An ex-Community Manager may turn out to be more competent than a Head of Community, depending on the scope of their role and their position in the organisation. As job titles are still very fluid, use this question to flesh out just how experienced they are and whether they were running teams or influencing any other departments.