Perhaps Facebook no longer fully understands its own tangle of algorithms—the code, all sixty million lines of it, is a palimpsest, where engineers add layer upon layer of new commands. (This is hardly a condition unique to Facebook. The Cornell University computer scientist Jon Kleinberg cowrote an essay that argued, “We have, perhaps for the first time ever, built machines we do not understand. . . . At some deep level we don’t even really understand how they’re producing the behavior we observe. This is the essence of their incomprehensibility.”
