Scythe by Neal Shusterman

Death has been defeated and world peace achieved. With the guidance of Artificial Intelligence, humanity has ushered in a utopia…. mostly. In Scythe, Neal Shusterman posits that AI has evolved into an omniscient (and omnibenevolent) force called the Thunderhead, through which the world has achieved a true and lasting peace. The Thunderhead controls everything, but unlike many dystopian works, this is a miraculous and profoundly beneficial event. The only power that the Thunderhead does not possess is the ability to take life.