He was hailed as Walmart’s online guru, the guy who would drag the lumbering giant into the digital-commerce era and put Amazon in its place.

But 18 months after selling his startup to the world’s largest retailer, Marc Lore is finding those expectations awfully hard to meet. It’s not that investors and analysts are giving up on him as much as it’s a realisation that the task at hand is daunting and growing harder by the day - and that Lore has little margin for error.

Walmart’s online sales over the critical holiday period grew at less than half the rate of previous quarters, while investments Lore’s making to enhance the e-commerce business dented profitability. The results sent shares tumbling and prompted a report, which Lore denied, that he was considering stepping down.