The veteran ad sales chief's surprise departure raises questions about her own future, and the future of the platform formerly known as Twitter.

Linda Yaccarino is stepping down as CEO of X after two years running the company, she announced today. She was appointed its CEO in the year after Elon Musk bought and renamed the company previously known as Twitter — so far, there is no word on who will replace her.

Former NBCU ad exec Linda Yaccarino’s tenure at X may have been fairly short — just two years from start to finish — but she did manage to make an impact on the social network’s ad business, new data from ad intelligence firm Guideline shows. Yaccarino will be leaving X in a better position with its advertisers than she found it, it says.