Singular focus on audience development expresses itself in different ways at different publications. At The Huffington Post, it takes the shape of an editorial mandate that, much like the universe itself, is unfathomably broad and constantly expanding. At least in theory, nothing gets past its editors and writers. They cover, in most cases through aggregation, everything from Federal Reserve policy to celebrity antics, from Islamic State atrocities to parenting tips, supplemented with a steady stream of uncategorizable click bait (‘‘Can Cannibalism Fight Brain Disease? Only Sort Of’’).To work at The Huffington Post is to run a race without a finish line, at a clip that is forever quickening.