I did overall enjoy reading the book, but there are pretty glaring flaws.
Ying disguises herself as a boy and leaves home to investigate her father's murder, and she just so happens to get the chance to enter the trial to join the engineering guild. Her goal to get into the guild quickly seems to overshadows her goal to learn about her father's death, and I don't think the story balanced these plot points evenly. The engineering tests are interesting enough, but I do wish the stakes were higher. I felt like if Ying failed she could just go back to her original plan of trying to learn more without undergoing the tests. Ying herself is an ok protagonist, but I think she's pretty mean to her best friend. Ye-kan was truly the best part of this book. But I think I kept reading more because I was curious of the plot than because I cared about the characters.
The writing was mostly pleasant to read, but one pet peeve of mine is when the character seems to always notice someone's eye color. She was really obsessed with the eye color of her love interest's family.