YouTube CEO Susan Wojcicki is stepping down from the role after nine years running the Google video division, handing the reins to top lieutenant Neal Mohan.

Wojcicki said in a blog post that she planned to “start a new chapter” focused on her family, health and personal projects. She’ll also take an advisory role, working across Google and parent Alphabet Inc.

“The time is right for me, and I feel able to do this because we have an incredible leadership team in place at YouTube,” she said.

Wojcicki is one of Google’s longest-serving employees and one of the highest-profile female executives in Silicon Valley. After lending her garage to the company’s founders, she joined as an early marketing manager and rose through the ranks of Google’s advertising business.

In 2014, Google’s then-CEO, Larry Page, tapped Wojcicki to run YouTube, an online video company that Google acquired in 2006. For years, YouTube had expanded ferociously but struggled to become profitable. Wojcicki brought a renewed focus on challenging the TV ad market, boosting YouTube’s creators and its ties with media companies.

But Wojcicki also oversaw YouTube’s rockiest years. Under the Donald Trump presidency, the platform struggled with issues around extremism, disinformation and child safety. Major advertisers boycotted the site multiple times in 2017. Since then, Wojcicki has gradually built trust back with advertisers and expanded YouTube’s TV streaming service.

Mohan has been Wojcicki’s top deputy for years, moving over from Google’s ads business to YouTube in 2015. He was widely seen as her natural successor.

“Susan has a unique place in Google history and has made the most incredible contribution to products used by people everywhere,” co-founders Page and Sergey Brin said in a joint statement. “We’re so grateful for all she’s done over the last 25 years.”

—Bloomberg News