How Mark Zuckerberg's old teaching assistant at Harvard rose to become Meta's CTO and a key lieutenant

In the interview, he said his family have lived on the ranch since 1891, and he has tattoos of California, a grizzly bear, and golden poppies tattooed on his right forearm.

Boz was a teaching fellow for an artificial intelligence course Zuckerberg took.

"Facebook came out on February 12, which was two weeks after finals ended for CS182, so he was clearly working on Facebook instead of studying for my class," Bosworth told Harvard for an alumni profile in 2020. "Clearly, Mark was a guy who was building things, but none of us had any idea what Facebook would become."

Zuckerberg dropped out of Harvard during his sophomore year in 2005 to focus on Facebook full-time.

He was a developer on flowchart and diagramming software Microsoft Visio for almost two years, according to his Meta profile.

In a 2021 interview with The Verge, Bosworth said his brief time at Microsoft taught him a lot about "professional software development and management."

He started working for Facebook in 2006.

He recalled to The Verge that when he joined Facebook, there were roughly 15 engineers working at the company, adding that there are only five or six employees who have been at the company longer than him.

"I built all the AI, the ranking, and we built the first, as far as I know, the first ranked content feed, and I built all the rank and the AI behind it," Bosworth told The Verge.

"It consumed me more fully than anything in life had ever consumed me," Bosworth told The Los Angeles Times in 2011. 

Bosworth also told The Los Angeles Times that the News Feed was initially met with a backlash from users, who found it too intrusive.

"That passionate outpouring of sentiment, much of it negative, was being fueled by News Feed itself. That's when I realized how big the opportunity was at Facebook. I would have preferred a fan group to a protest group, but the fact that people felt that passionately about the product at all was very humbling and eye-opening," Bosworth said.

As Bosworth's career at Facebook progressed he went on to lead teams that built products,  including Facebook Messenger and Groups.

In a 2015 interview with Wired, Bosworth said six months ahead of the planned sabbatical in 2012, Zuckerberg asked him to figure out a way to monetize ads on mobile.

"[Zuckerberg] was like: 'There are at least four billion-dollar opportunities on mobile in the next six months. You can unlock one or two. And then you can go on your vacation.' That's an insane thing to say. But I was like: 'Why not?'" Bosworth told Wired.

Two days before Bosworth was supposed to go on his sabbatical, Zuckerberg asked him to head up engineering for all Facebook's advertising products, and Bosworth accepted.

Bosworth ended up taking a two-month trip and then tacked on some extra time off at the end of the year. " I just kept taking it by halves," he told Wired.

Bosworth ran Facebook's ads business until 2017.

Reality Labs has undergone many name changes, having been called simply AR/VR, then Facebook Reality Labs, and now Reality Labs.

Reality Labs has been responsible for producing Facebook hardware products including the Meta Quest VR headsets and Meta's various Ray-Ban smart glasses.

When Zuckerberg announced the formation of Meta as Facebook's new parent company in October 2021, he said the business would be split into two strands. The first is Facebook's Family of Apps, which is its traditional social media business that encompasses its Facebook app, Instagram, and WhatsApp.

The second and more metaverse-centric strand will be Reality Labs. 

"From now on, we'll be metaverse first, not Facebook first," Zuckerberg said during the company's announcement of its rebrand.

The word metaverse is a term borrowed from science-fiction. It refers to a future version of the internet, which people access using technology such as virtual-reality and augmented-reality headsets, rather than screens on phones and laptops. 

The Ray-Ban Stories glasses launched in September 2021, and allow users to capture photo and video.

Bosworth shared a video taken with his own Ray-Ban Stories ahead of the product launch,  which included footage of himself repeatedly throwing pillows at Mark Zuckerberg.

Bosworth replaced Mike Schroepfer as CTO, marking the biggest leadership change in the company's history.

In a Facebook post announcing his departure, Schroepfer talked about Bosworth's experience at Facebook's AR/VR division.

"These contributions are foundational components of our broader efforts to help build the metaverse," Schroepfer said.

Zuckerberg echoed this in a statement on Facebook's blog.

"As our next CTO, Boz will continue leading Facebook Reality Labs and overseeing our work in augmented reality, virtual reality and more, and as part of this transition, a few other groups will join Boz's team as well. This is all foundational to our broader efforts helping to build the metaverse, and I'm excited about the future of this work under Boz's leadership," Zuckerberg wrote.

Bosworth made headlines in 2018 when BuzzFeed published an internal memo he had sent around two years previously. The memo was entitled "The Ugly," and in it, Bosworth appeared to justify any number of horrible things happening on Facebook, so long as the company continued to grow.

"The ugly truth is that we believe in connecting people so deeply that anything that allows us to connect more people more often is *de facto* good. It is perhaps the only area where the metrics do tell the true story as far as we are concerned," Bosworth wrote in the memo.  

"That isn't something we are doing for ourselves. Or for our stock price (ha!). It is literally just what we do. We connect people. Period," he added.

"Boz is a talented leader who says many provocative things. This was one that most people at Facebook including myself disagreed with strongly. We've never believed the ends justify the means," Zuckerberg said.

During a committee hearing in front of Irish lawmakers in 2018, then-head of public policy at Facebook Ireland Nimah Sweeney also said Bosworth has a "reputation for posting provocative material to get a conversation going" inside the company.

"I think a lot of us would like to go back and hit delete before he ever managed to send that," Sweeney added.

Business Insider first reported on the August 2020 memo entitled "Demand Side Problems," which was contained in a cache of documents released by Haugen.

In the memo, Bosworth appeared to question whether it was futile for Facebook to try to address hate speech on its platforms. Bosworth also posted the memo to his personal blog in early 2021.

"As a society we don't have a hate speech supply problem, we have a hate speech demand problem," Bosworth wrote.

"Online platforms don't work on the supply side because they don't control the demand side," he added. 

Bosworth's technology podcast began in June 2021 and has featured appearances from fellow Facebook executive Chris Cox, as well as tech journalists Ina Fried and Casey Newton.

Bosworth said on Lenny's Podcast this year that when Zuckerberg decides an employee is working on one of the company's most important projects, he'll zero into even the most minute details, applying an "Eye of Sauron"-like intensity.

As far as giving Zuckerberg feedback goes, Boz says Meta's CEO will "most often tell you that you're wrong" but ultimately ask others what they think in an attempt to "pressure test" the proposed ideas or feedback and consider it from new perspectives. Eventually, Zuckerberg makes the changes even though he dismissed them at first, Boz said.

"It's uncanny," Bosworth said in the podcast. "Over the course of the next like week or two, you'll just see shifts."

Boz said Apple's mixed-reality headset, a rival to Meta's Quest VR headsets, was "very uncomfortable to use."

"I think it's way too much weight. And it's distributed poorly," he said shortly after the Vision Pro launched in the US in February.

"As soon as I put the headset on, I can see what trade-offs they made and why they made them. And, perhaps definitionally, those aren't the trade-offs I would have made," he said.

He's also shot down speculation that Meta rushed to announce its Quest 3 headset ahead of Apple's Vision Pro debut. Meta announced its device four days before Apple unveiled its counterpart at WWDC last year.

"We sent a note to Mark long before we even knew about WWDC timing or substance: 'Hey for Quest 3, we want to announce it early so that people know it's coming so that they can plan well in advance of the holiday season what they want to do,'" he said.

The Meta CEO also regularly answers questions on Instagram in an AMA-style format.