After Failing to Lie Flat, I Became the Hardest Worker in the Six Palaces

Transmigration, a Favored Concubine, and an Ancient Setting: Palace Intrigue and Workplace Politics

Looking for books like I'm Just a Concubine, So Why Is Everyone Clinging to Me? The writing is witty and humorous, and the plot threads fit together seamlessly. The heroine is adorable and always clear-headed. She seems to have given up on life, but she's mastered all the workplace rules and understands human nature inside out.