Redundancy and complacency cause many humans to bail out of existence and dwell in Heaven. Most of the remaining jobs require the remarkable skill set of vampires (who are no longer extinct), after all, or your human brain needs so much upgrading and retraining in order to be useful that you may not be much like a human anymore.
Maybe it's easier if you just had half of your brain removed as a child because of a developmental disorder; it may have removed most of you, but no one remembers you anyway, and it left a lot of room in there for useful gadgets. They help you do your job very well. Your job is sort of a translation gig, though that's an insulting simplification.
When the aliens suddenly allow their existence to be known, you're sent along with a team to attempt communication. Too bad they don't particularly want to talk to you, though. Or to your multi-personality linguist.
...It's hard - for me, at least - to talk about the characters and plot of this book without stepping over into gross spoiler-territory. Or, I think so, because this is a novel that is thick with so many cool THINGS; the reading experience is at least as much about the continuous introduction of awesome tidbits as it is about the, uh, story. It's simply one of the coolest books I've read in a long, long time. It opens with a Ted Bundy quote, which is, oh, appropriate.
Peter Watts has been recommended to me several times over several years. I've made note of it and had thoughts like "Cool, he makes his book available for no money", and yet his name has kept getting pushed back in the to-read pile. (Dear friends-who-recommended: Yes, yes, I will listen carefully next time you say I have to read a thing, I trust you now.) Finally getting around to reading Blindsight was the result of having it on the kindle already and being aware that a sort of sequel, Echopraxia, is coming. (Which is not going to be postponed indefinitely on my reading list, no.)
This isn't a review as much as it's just Abed from Community going "Cool cool cool" with glazed-over eyes. Do I want to point out any flaws with the book? No, I don't. Except for how, if it maintained the density of cool, I would have welcomed another thousand pages of it. (But did I mention Echopraxia?! I HAVE ECHOPRAXIA.)