Exodus / Alex Lamb.

Originally published in Great Britain in 2017 by Gollancz, a subsidiary of Orion Books.

"The Photurians - a hivemind of sentient AIs and machines - were awakened by humanity as part of a complex political trap. But they broke free, evolved, and now the human race is almost finished. Once we spanned dozens of star systems; now only four remain, and Earth is being evacuated. But the Photes can infect us, and among the thousands rescued from our home world may be enemy agents. Tiny colonies struggle to house the displaced. Our warships are failing. The end of humanity has come. But on a distant planet shielded from both humanity and the Photurians, one hope may still live. The only person who might be able to intervene. The roboteer. He is trapped in a hell of his own making, and does not know he is needed. And so a desperate rescue mission is begun. But can he be reached in time? Or will he be the last remnant of humanity in the universe?"--Publisher's description.