Sources: Sam Altman had sought to delegate more responsibility for months before hiring Fidji Simo, an adept and detail-oriented manager, in contrast to Altman (Wall Street Journal)

Wall Street Journal:
Sources: Sam Altman had sought to delegate more responsibility for months before hiring Fidji Simo, an adept and detail-oriented manager, in contrast to Altman  —  Fidji Simo is leaving Instacart for a newly created role at Sam Altman's startup as it prepares for a potential public offering