I don't know why Children of Ruin came to my mind instead of Children of Time, but I agreed that the first book is more focused in the spiders. I was told that there is already a third book that end that serie, Children of Memory, gotta read this one! ...
This reminds me of this sci-fi book called Children of Ruin where in a terraformed world, a genetics experiment goes wrong and the whole place is now overrun with super-intelligent giant spiders, who were infected with the uplift virus and have built their own civilization in the meantime — and who are protected from orbit by the immortal computer intelligence of Avrana Kern, who has determined in the intervening centuries, that she likes the spiders better than people... Nice reading! Recommended!