New Delhi, July 21 -- Fidji Simo has stepped down from her full-time role at OpenAI for health reasons.

It is not yet the PayPal mafia, but the Instacart matriarchy is making its mark. Not long after Fidji Simo, ex-head of the online grocery store, became Sam Altman's product-focused sidekick at OpenAI, Asha Sharma, Instacart's former chief operating officer, became Satya Nadella's Ms Fix-it at Microsoft Gaming. Groceries are a tricky, low-margin business. So is Xbox-and Ms Sharma has wasted no time in getting to work. On July 6th, less than five months after becoming the division's boss, she launched what she called the biggest reset in its 25-year history.

Ms Sharma has gone about her overhaul with a candour that is rare in the mealy-...