Scale AI founder Alexandr Wang is leaving the company to join Meta as part of a $14.3 billion investment deal, which will give Meta a 49% stake in the startup without voting power. Jason Droege, Scale AI's chief strategy officer, will succeed Wang as CEO, while a few employees will transition to Meta as well. This move aligns with Meta CEO Mark Zuckerberg's emphasis on enhancing AI capabilities amidst competition from other tech giants.