For her senior project, a coding prodigy invents an app called MASH that predicts users' future outcomes in life, never imagining it will become a public sensation.Eighteen-year-old Rose Devereux lives with her devoted father in small-town Colorado, having largely put her tech genius mother's abandonment of their family when she was little behind her. Her behavioral scientist neighbor, Vera, is like a grandmother to her and has been battling cancer for the last three years. Vera and Ro worked together to develop the predicating theory behind MASH. When the app is unexpectedly promoted by Ro's social media influencer cousin, Ro is drawn into a partnership with a Silicon Valley firm that insists the hook is the aspect that predicts someone's life partner. Pushed to win over funders by using herself as an example, Ro publicly stages a relationship with Alistair Miller, a sensitive, brainy boy she grew up with but from whom she is estranged. There are some interesting ideas explored along the way about free will and ambition, and Ro's family experiences, including Vera's illness, provide for convincing emotional drama, but the central focus of the story is on the romance, which will please fans of the genre. The main characters read White; there is some ethnic diversity suggested by secondary characters' surnames, and Ro's best friend is in a same-sex relationship.A thoughtful meditation on some weighty questions wrapped in a well-drawn romance. (Romance. 13-18)

Eighteen-year-old Rose Devereux thinks her dreams are coming true when MASH, the mobile app she developed in collaboration with her elderly behavioral scientist neighbor, Vera, goes viral, capturing the interest of tech corporation XLR8. Though her father forbids her from partnering with XLR8, citing that continued development of the app will detract from her academics, Ro agrees to work with them anyway, hoping to prove she doesn’t need college to launch her cyber career. To further promote MASH, which can predict a person’s ideal romantic partner with 93% accuracy, XLR8 encourages Ro to take the app’s survey herself and pursue her predicated true love. When she’s matched with Alistair Miller, her former best friend whom she believes “thoroughly hated” her, she endeavors to persuade him into a highly publicized, pretend romance. O’Clover’s prose, brimming with dry wit, pensively ponders existential questions regarding free will and the “gray area” of human behavior that no computer can measure. A nuanced cast navigating evolving interpersonal struggles—including Ro’s relationships with her absent mother, Miller, and Vera—and natural-feeling dialogue elevate this tech-driven debut about love, fate, and change. Main characters present as white. Ages 13–up. (Jan.)