Tankborn by Karen Sandler

Best friends Kayla and Mishalla know they will be separated for their Assignments. They are GENs, Genetically Engineered Non-humans, and in their strict caste system, GENs are at the bottom rung of society. GENs are gestated in a tank and sent to work as slaves as soon as they reach age fifteen.
When Kayla is Assigned to care for Zul Manel, the patriarch of a trueborn family, she finds secrets and surprises;not least of which is her unexpected friendship with Zul's great-grandson. Meanwhile, the children that Mishalla is Assigned to care for are being stolen in the middle of the night.
After weeks of toiling in their Assignments, mystifying circumstances enable Kayla and Mishalla to reunite. Together they hatch a plan to save the disappearing children. Yet can GENs really trust humans? Both girls must put their lives and hearts at risk to crack open a sinister conspiracy, revealing secrets no one is ready to face

I think this is the Young Adult book that the adult science fiction fans have been waiting for. Tankborn is not only an excellent science fiction dystopian, but it shares the hallmarks of classic science fiction: excellent worldbuilding, a scientific foundation, morality that leads to more questions than answers, and a plot that ties them all together. Sandler’s take on class warfare and the solutions to it are interesting as reflections to our modern issues. Her characterization of Kayla is sympathetic and believable. The world of Loka is incredibly detailed, and unlike a lot of modern dystopians, where you feel that the author is making up the world as they need it to advance the plot, with Sandler you get the feeling that there is so much more to Svarga than presented. The plot has great twists that come out of nowhere and yet still seem like reasonable follow-ups to the action that happened before them.

I’m a little more conflicted on the cover, though. While I really want to congratulate the publisher for putting a person of color on the cover, I can’t help but point out that the society in the book is pretty clearly Indian, and conflating African heritage with South-Central Asian is not really helping. People of color have distinct societies and heritages, and making them all a homogenous mish-mash because they’re “NOT WHITE” is part of the problem, not part of the solution.

Nonetheless, Tankborn is an excellent book, and should be considered for a Hugo next year for its appeal to readers of all ages.