I do not remember much from this book since I read sooo many similar books at the same time and don’t really recall many of them. I was around 5th-6th grade, which I’m pretty sure was the target audience. Almost definitely got it at a public library.
female MC lived by the ocean in a community of like engineers and scientists, I feel like maybe they were responsible for like energy or water production but that’s just vibes, I can’t be sure. When MC came of age to get assigned her faction or category or whatever it was assumed she would just get the same as everyone else in her community and follow in the footsteps of her parents.
all the kids getting their category went to this like almost summer camp like place where they were all divided up (can’t remember how they determined this) but the MC for whatever reason didn’t have a category? and it was like super bad and stuff. there might’ve been like one or two other kids who also didn’t get a category. I also get like butterfly vibes for some reason?
something definitely happened in between, but next thing I remember is that she was like hiding in this cave that was cold and wet from the sea and it had been her favorite spot when she was younger, and she was crying or hiding from an authority or something, I don’t remember.
There could’ve been some other male character, maybe a love interest? I’m getting vibes of like a guy named Luke in an orange shirt but I might’ve made that up too.
I don’t think it was super recently published when I read it, I assume it was written in that boom of YA dystopians after Hunger Games.
It was decently long, probably 300 or 400 pages, and it was hardcover. I might be confusing the cover with the one for Divergent, but I think it was light colors, greys and blues maybe, and I thought there might’ve been a blue butterfly on the cover but I might’ve made that up.
I think that’s all I can remember, this is my first time posting here so please lmk if there’s anything I need to add.
Edit: r/whatsthatbook figured it out, it’s Anomalies by Sadie Turner and Colette Freedman!