I have not heard of Yoon Ha Lee, but plenty of people have. The basis of his SF is math, and he is now devoting most of his time to the Machineries of Empire universe, of which Ninefox Gambit is the first full length novel.
The technology here is the calendar--the regulation of life by holidays and appointment. The calendar can be used as a weapon, and rebels against it make use of those properties as well. It's a sort of magic, though never discussed as such here.
There's lots of action and intrigue, and much to enjoy. Yoon Ha Lee has plenty of fans. But I have to say I found the book hard to read, and it never really took off for me. It could be a lack of familiarity with the cultural context--it is apparent that Lee is making different assumptions from what Westerners would. Still, I spent a lot of my time reading this book confused. I don't think that's how action novels are supposed to work.
I guess this reminds me of Aliette De Bodard's work--confusing when it should be transparent. It still sort of works, but I can't say I favor it for an award. A weak 3 stars from me.