Christina Miller, president of Cartoon Network, Adult Swim, Boomerang and TCM, said she’ll be leaving the company at the end of the year, after a 15-year run at the company (which is formerly known as Turner).

Michael Ouweleen, evp and CMO for Cartoon Network, Adult Swim and Boomerang, will serve as the interim president following Miller’s exit.

“This is not a decision I came to lightly,” Miller wrote in a staff memo. “It’s one of the hardest I’ve had to make in my career. Ultimately, it feels like the right time for me to leave and take a little time to think about what comes next, but I do so feeling immensely proud of the work we’ve done together and so grateful for the experience.”

Miller has led Turner’s kids and young adults division for the last five years, overseeing all aspects of  Cartoon Network, Adult Swim and the SVOD streaming service Boomerang. She more recently added TCM to her portfolio. Adult Swim has been the No. 1 cable network in adults 18-34 for several years under her leadership.

She was previously gm of NBA Digital and svp of Turner Sports strategy/marketing/programming. Before joining Turner, she was svp of brand management and licensing for HIT Entertainment. Miller joined Turner in 2005 as vp, Cartoon Network Entertainment

“Christina has been a respected and impactful leader since she joined the company,” said Warner Bros. chair and CEO Ann Sarnoff in a statement. “We wish her the best of luck in the next chapter of her career, where I know she’ll continue to enjoy great success.”

Miller’s departure is the latest in a long line of high profile WarnerMedia exits this year as parent company AT&T restructured the organization.

In February, HBO CEO Richard Plepler and Turner president David Levy departed in a major shakeup of WarnerMedia leadership. A month later, Warner Bros. chairman and CEO Kevin Tsujihara resigned following sexual misconduct allegations.

WarnerMedia ad sales chief Donna Speciale left in July, just after wrapping upfront negotiations. Her replacement still hasn’t been named. Also departed in that ad sales shakeup was Dan Riess, evp of Ignite, who had also launched the Courageous branded content studio, and Frank Sgrizzi, evp of portfolio sales and client partnerships.

Unlike many of those forced exits, Miller had been asked to remain at the company and chose to leave herself, according to a company source.