Elon Musk's AI startup xAI has poached AWS’ head of data center network strategy to lead its machine learning infrastructure buildout.

Saurabh Kumar, who had worked as a principal engineer for data center networking at Amazon’s public cloud platform for almost nine years, joined xAI in December.

Writing on LinkedIn, he said: "After ~9 years leading data center network strategy at AWS, I have decided to take on a new challenge.

“It was a privilege to work alongside the exceptional talent at AWS and shepherd its transformation from a consumer of network technology to an industry-leader, driving bleeding-edge products across multiple networking domains.”

Kumar said his new role at xAI will “focus on ML infrastructure,” and that he has been tasked with “building teams, processes, and interconnect products from GPUs to Backbone.”

He added: “After a decade of speeds-and-feeds, we find ourselves at a critical juncture for data center networks - emerging modalities like CPC, NPO, CPO, THz radio; technologies like ring resonators and TFLN, OCS-based reconfigurability, and the mandate to identify and champion the most power-efficient approaches to stay in lock-step with GPU cadence while accelerating buildouts and improving build quality.

“I look forward to delivering the network infrastructure for massive-scale compute gigafactories powering the innovative products at xAI.”

Previously, Kumar has spent a decade working at Infinera, the California networking firm acquired by Nokia last year for $2.3 billion.

xAI is the developer of the Grok chatbot and has been investing heavily in digital infrastructure over the last two years to power its system, which it sees as a rival to OpenAI’s ChatGPT.

It already operates two data centers in the Memphis area, one in the city itself and another just over the border in Mississippi. In December, Musk announced the firm had bought a third building in the area, and plans to turn it into a data center that will bring the company’s available compute power to just under 2GW.