This is exactly the sort of steampunk I've been looking for for months. Most obviously, there's the sexual politics. Mattie is a machine, but she's a female machine, with all of the structural undergarments that a live woman would have to wear for the purposes of 19th century fashion built permanently into her body. She was made to serve, but she has the abilities to think and to feel pain and pleasure. To an extent, through asking to learn alchemy, she has managed to create a life for herself, but it's unclear if she even is in any legal sense emancipated or if her creator, Loharri, merely allows her to live alone and tend to her own affairs most of the time. But he keeps her bound to him in various ways, including keeping the key she needs to be wound. Their relationship was complex, often coercive at best and abusive at worst, but fascinating. Loharri is cruel but it comes from a place that is more pathetic than anything else. He's afraid of losing her, so he builds things into her that force her to visit him, thereby giving her more reasons to escape. It's the system that is broken and everybody in it is damaged. After Mattie develops a plan to get her key from him, the thought crosses her mind that she could give it to the (human) man she loves, but she rejects it quickly, resolving that once the (female) allies who are getting her key give it to her, she will always wind herself in advance so nobody else will ever touch it again. The problem isn't who has the power, it's anybody else having the power.
Then there are the racial angles. Some of them are explicit. After an attack on the city, the Easterners living there are suspected and hounded by the authorities. But in addition to the literal racial conflicts among the humans, there's also an extent to which Mattie is a stand-in for women in racial minorities, a minority in a minority who suffers additional acts of oppression often ignored by her friends Iolande and Niobe on the grounds that there are more important things they need to do, and who sometimes feels excluded from the world of women made of flesh.
There are the class issues surrounding industrialization. The alchemists and the machinists have been in competition since people began building machines, but the real rebellion comes from the proletariat workers who have lost good jobs to machines, and who work in the mines where automated brains make decisions about how they will work.
There was a plot thread involving gargoyles that I never fully understood. When it came up I felt like I had unknowingly started in the middle of a series and was supposed to start with background information that I didn't know. But I love how all encompassing the book's study of the world within it was. It can hold its own against any social science fiction.
Overall: A-