A wise fox does eat near its own den

Betrayed by a scumbag and with her career in ruins, the female protagonist finds herself in a desperate situation and applies for a job at a top-tier conglomerate. Unbeknownst to her, the CEO hiding his identity is actually the ex-boyfriend who left without a word three years ago. As an old flame reappears in an unfamiliar form, how will she navigate this complicated situation?