3.5/5 stars.

3 stars for the character building and storytelling, but 5 solid stars for the setting, scenery, culture, and worldbuilding!
I loved loved loved getting to read a book with middle eastern characters and settings without those things being what the story was 'about.' Chakraborty writes assuming you know about the culture without explaining every little thing, which made me do some of my own research (there's a glossary too).
That being said, I was extremely underwhelmed by the story writing. Every character was basically the same in how they spoke and thought - there were no distinct differences in the voices between the two POV's and really between any of the characters. There were many times (especially in the first 2/3 of the book) that I felt it falling into the 'too much' trap with trying to be mysterious and epic, and in doing so lost the reader a bit. I got a little lost with time passing in the novel - had it been a week? A month? A day? And a little frustrated by the inconsistencies in character actions and voices.
I will be reading book 2 and hoping a lot of these things get resolved as the author grows in her writing!