I started reading and immediately thought of Blindsight. The tweet thread mentions it later, make sure to check it out if you like hard sci-fi, it's one of the best.
Blindsight is one of the best, 10/10 on Mohs Scale of sci-fi hardness. I love the description of scientific concepts behind sci-fi story at the end. Such a shame, there is so little books with that kind of deep research.
One of the best written, first contact novels out there. I have the luck of hearing Watts lecture on one of the Cons. He is even better in person.
If you are from Canada, it is good idea to check, where he is speaking.
Authors blog, filled with pop-scientific concepts and ideas [1], is well worth it.