Finished Children of Time by Adrian Tchaikovsky earlier today. I'm totally normal about it I promise. My good friend @daisywalletchains introduced me to the series.
She said something like, "there's spiders that become sentient and sapient and you get to follow them as their society progresses" and I was SOLD. There's a lot more to it than that obvi, but oh my GOD it's good.
Plot A surrounds Dr. Kern, a human at the tail end of Imperial human society, and her project to grant some other species sentience so humanity doesn't have to be alone in the cosmos. This...goes wrong. And instead of monkeys, she gets spiders. And we get to watch those spiders form society.
Plot B surrounds the Gilgamesh and it's crew (specifically, Holsten Mason). The Gilgamesh is an Ark vessel sent out long after the collapse of human society, seeking to find a new planet with a crew placed in cryostasis.
It's really good. Really REALLY good. You should read it. There ARE spiders though. Lots of spiders. Lots of BIG spiders. But by the end of the book, the spiders seem (to me) almost more sympathetic than the last human survivors. It's wild.