Joëlle Pineau, the head of artificial intelligence (A.I.) research at Meta Platforms (META), is leaving the company.Pineau's last day at Meta Platforms will be on May 30, 2023.Meta CEO Mark Zuckerberg has made A.I. the company's top priority and aims to build an A.I. assistant with over one billion users.Pineau, a prominent A.I. researcher, joined Meta Platforms in 2017 and led the company's fundamental A.I. research unit.