Nscale has raised billions to power Europe’s AI ambitions. Now the startup must prove the hype can survive reality

(Credit: Arctic Media House/Courtesy of Nscale)

Sheryl Sandberg has a habit of joining tech firms before they become household names. She joined Google at roughly 250 employees and Facebook at 550. When Josh Payne set out to recruit her to the board of his AI infrastructure startup Nscale, it was a letter to his management team that convinced her she’d found another one.

“The only person I’d ever seen write like that was Mark [Zuckerberg],” Sandberg tells Fortune. “It was so clear, so thorough, but so big in its vision.”