The Chief Executive Officer of X (formerly Twitter), Linda Yaccarino, has resigned from her role on Wednesday morning, nearly two years after taking the helm of Elon Musk’s embattled social media platform.

“When @elonmusk and I first spoke of his vision for X, I knew it would be the opportunity of a lifetime,” Yaccarino wrote in her farewell post. “I’m immensely grateful to him for entrusting me with the responsibility of protecting free speech, turning the company around, and transforming X into the Everything App.”

Musk, who acquired Twitter in late 2022 and rebranded it as X, responded with a brief message: “Thank you for your contributions.” He has not yet disclosed plans for a new CEO.

Yaccarino’s abrupt exit comes just hours after X was forced to take down its AI chatbot, Grok, following widespread backlash over antisemitic messages posted by the bot. The timing of her departure — just ahead of Musk’s scheduled debut of Grok 4 — has sparked speculation about internal tensions.

A seasoned advertising executive, Yaccarino was hired in 2023 from NBCUniversal, where she served as Chair of Global Advertising and Partnerships. Her main task was to stabilize advertiser confidence during a volatile transition period as Musk assumed full control of the platform.

That job proved difficult. Within months of her appointment, Musk drew criticism for promoting conspiracy theories and engaging in public feuds with advertisers. His most notable outburst came during a live interview in November 2023 when he told companies boycotting X to “go f— yourself,” directly addressing Disney CEO Bob Iger.

Despite mounting pressure and advertiser exits, Yaccarino remained loyal to Musk, defending X as a platform committed to “free speech and Main Street.” But with Grok’s recent misconduct and the platform’s ongoing monetization struggles, her resignation may signal a deeper reckoning within the company’s leadership.