VERY much enjoyed this book. While I think it can be described as Young Adult, it's not very "young adult-y". The heroine is 19, and treated, by and large, as an adult.
Very much enjoyed the world building, but if you're looking for historical detail, this probably ain't the book for you. The world feels very real, but the story isn't really about broad political implications or anything, so you don't really get broad world building, you get stuff that Ceony notices and cares about. Particularly enjoy the magic system, it's very entertaining.
I found the romantic tension between Ceony and Emery Thane to be lovely and not TOO overblown. It's also working for me surprisingly well, despite normally greatly disliking student/teacher relationships.
I switched back and forth between reading and listening (kindle unlimited) and the audiobook version was beautiful. Lovely expression and phrasing.