Facebook on Tuesday confirmed an unprecedented management team shakeup in the aftermath of a major data privacy scandal that has rocked the social network.
Co-founder Mark Zuckerberg remained chief of Facebook, with chief operating officer Sheryl Sandberg his second-in-command.
Chris Cox, a longtime member of Zuckerberg's inner circle, was put in charge of Facebook's core application as well as smartphone services Instagram, WhatsApp, and Messenger, the California-based company confirmed.
The major shuffling of executives was first reported by technology news website Recode.
Facebook reshaped its product and engineering teams into three units, including an emerging technologies division focused on blockchain technology used for cryptocurrencies.
David Marcus said in a post on the social network that, after four years in charge of Messenger, he is "setting up a small group to explore how best to leverage blockchain across Facebook."
He expressed confidence in his Messenger successor, whom he identified as Stan Chudnovsky.
Longtime Facebook executive Javier Olivan will be in charge of a "central product services" division handling features such as security and ads that are common to various services run by the social network, according to Recode.
While more than a dozen executives saw their jobs change, none appeared to be leaving the company, US media reports indicted.
WhatsApp co-founder Jan Koum last month announced his departure from Facebook, which bought the smartphone messaging service four years ago for $19 billion.
Koum said in a post on his Facebook page that he is taking time off to pursue interests such as collecting air-cooled Porsches, working on cars and playing ultimate Frisbee.
US media reports indicated that a disagreement with Facebook over the privacy of user data may have also been a factor in Koum's decision to quit his position as a high-ranking executive and likely leave his seat on the board at the leading online social network.
WhatsApp boasts more than 1.2 billion users worldwide.
While not directly mentioned, the executive moves confirmed on Tuesday come as Facebook strives to move past the recent privacy scandal involving Facebook and Cambridge Analytica.
Zuckerberg spent most of the past month on the fallout from revelations on the hijacking of personal data by the political firm, seeking to assuage fears that the California-based internet colossus can safeguard privacy while making money by targeting ads based on what people share about themselves.
The social network is also among online platforms that came under fire for being used to spread misinformation and foment division ahead of the US presidential election in 2016.