most don't "brew it fresh constantly". they keep the pot on the burner until it is empty (or in newer hardware, store it in an urn that limits air exposure somewhat) until they need more. None I've seen actually time a brew set and throw it out when it hits that shelf-life counter, like Starbucks (let alone do individual pourover brewing like better coffee shops).
McDonald's requires their franchises to brew a fresh pot every 30 minutes (I'm not saying all do, but I've seen it happen often enough I'm pretty sure most stores follow the rule, McDonald's brand is built on consistency across stores).
They also source their beans from Gaviña, a well considered supplier, who I believe does the roasting as well.
