At my company (London based startup) we always call references to get a verbal reference and ask specific questions (what were their main weaknesses, what's the

At my company (London based startup) we always call references to get a verbal reference and ask specific questions (what were their main weaknesses, what's the best way to manage them to get the best out of them, etc.) rather than asking for a generic reference. For more senior hires we get backdoor references through our own network (with the candidates permission) to ensure the candidate isn't just giving us their friends, etc.