What Alexandr Wang says he learned from Mark Zuckberg's 'really long' WhatsApp DMs

• Alexandr Wang says Zuckerberg sends really long WhatsApp replies and sends them really fast.
• Zuckerberg's rigorous time management allows him to balance work and family, Wang said.
• Wang says Meta’s CEO "ruthlessly" prioritizes his time.

Alexandr Wang says he used to wonder how Mark Zuckerberg had time to write him such long WhatsApp messages.

Before Wang joined Meta to help lead its AI agent efforts, the Scale AI founder would occasionally ask Zuckerberg for advice. The replies, Wang said in an interview with David Senra on Sunday, were unexpectedly detailed.

"I would ask him a question on WhatsApp, and then he would write these really long responses," Wang said. "I was really confused. I was like, 'How does he have time to write these really long responses?'"

Wang, the public face of Meta's AI agent Muse, said he later came to a simple conclusion: Zuckerberg is unusually fast — and rigorous — at writing.

"He'll write a very rigorous, long response very quickly," Wang said. "It's a very impressive skill of his."

The anecdote offers a small window into how Zuckerberg, Meta's CEO, manages his time and makes decisions as he tries to remake the company around artificial intelligence.

Wang said Zuckerberg's packed schedule requires "ruthlessly" prioritizing his time: "The only way he's able to do that and be a good dad and be a good partner and all this other stuff is to just, like, ruthlessly prioritize."

Wang said that an introduction to Zuckerberg around 2021 or 2022 took roughly a year to lead to a first meeting. At the time, the two spoke only about once every six months, he said.

But Zuckerberg’s involvement increased as Meta confronted shortcomings in its Llama 4 AI model and the growing stakes of the race against rivals such as OpenAI and Anthropic.

Wang said Zuckerberg called him to ask what Meta should do next and how it should think about its AI strategy.

Their conversations quickly expanded beyond advice. Within five or six weeks of Zuckerberg’s initial outreach, Meta announced a deal to take a 49% stake in Scale AI, while Wang and several colleagues moved to Meta.

Wang has since become a key figure in Meta’s attempt to rebuild its AI organization around a smaller, flatter group of top researchers.

He said Zuckerberg’s willingness to seek feedback from prominent entrepreneurs is a notable trait in a leader who has run Meta for more than two decades.