Susan Wojcicki, CEO of YouTube and one of the original Google workers, said on Thursday that she was leaving the company she helped create in her garage nearly 25 years prior. She made the announcement in a personal update on the video-sharing website.

Neal Mohan, Wojcicki’s deputy, will take over for the 54-year-old.

The change of guard comes as YouTube’s advertising revenue fell for the second straight quarter amid intense competition for viewing time with short-form video services such as TikTok and Facebook’s Reels, and streaming services like Netflix.

One of the most prominent women in tech, Wojcicki said she will focus on “family, health, and personal projects”, and plans to take on an advisory role at Alphabet.

She was previously senior vice president for ad products at Google and became the CEO of YouTube in 2014.

Mohan, a Stanford graduate, joined Google in 2008 and is the chief product officer at YouTube where he been focusing on building YouTube Shorts and Music.

He previously spent nearly six years at DoubleClick, a company Google acquired in 2007, and later served for about eight years as senior vice president of display and video advertising at Google.

Alphabet shares were barely changed for the day, down less than 1% after the news.