Looking for very hard/intellectual scifi with a thriller or creepy twist

I'm looking for very hard scifi and stories with a thriller or horror twist.

I like stories that weave complicated but internally consistent science/fiction to uncover; doing good science and people being smart in the face of the unknown is my jam.

I loved the scenes in Blindsight by Peter Watts where they were first onboard the Rorschach; I'm halfway through and that actually sparked this request. I also like books that make me work hard intellectually, either drawing on head knowledge of science/tech (I love Accelerando by Charles Stross for this) or biology (I'm in the medical field), or asking you to think a lot (Primer, Upstream Color, and Dark are some of my favorite movies/tv show). I've enjoyed There Is No Antimentics Division, Fine Structure, and qntm's corpus of short stories. I've liked (Tender is the Flesh) or been reluctantly transfixed (Cows) by the horror I've read; I'd particularly be interested if there is hard sci fi horror.

Some Other Things I've Read for Context

Schild's Ladder is one of my favorite hard sci fi books. Three Body Problem was a fascinating premise but I think the semantics of the translation didn't quite do it for me and there were a lot of glossed-over bits where I really wanted the story to dig in and explain. This is How You Lose the Time War was much more poetic than hard but I adored it and cried a lot (excellent). I've read everything by Neal Stephenson many times. Enjoyed the Laundry Files by Charles Stross. Wayfarers and Monk/Robot by Becky Chambers were cute and light. Altered Carbon rocked. Andy Weir's works were light but up my alley. Prey by Michael Crichton was formative.

Anyone have any recs? Thanks!!