OpenAI has hired four employees from rival companies including an AI researcher from Meta, signalling the Sam Altman-led firm won't take things lying down after Mark Zuckerberg-helmed tech giant has been on an aggressive poaching spree in the past weeks.

OpenAI has also roped in David Lau, former vice president of software engineering at Tesla; Uday Ruddarraju, former head of infrastructure engineering at xAI and X; and Mike Dalton, another infrastructure engineer from xAI, the Wired first reported.

From Meta, OpenAI has hired Angela Fan.

Greg Brockman, president and co-founder at OpenAI, welcomed all of them in an X post.

Ruddarraju's LinkedIn profile was updated to say he had quit xAI, which he had joined just last year. In a post, he also said that he worked on xAI's conversational AI Assistant Grok 3 and Colossus, believed to be the world’s largest supercomputer comprising more than 200,000 GPUs. 

Earlier this month, xAI had raised $10 billion in debt and equity.

OpenAI's hiring of these employees comes after rival Meta has been aggressively luring employees from rivals including OpenAI to beef up its superintelligence team.

Just earlier this week, Meta roped in Apple's top executive Ruoming Pang in charge of artificial intelligence models.

Zuckerberg went on a hiring spree after first making a significant investment in data labeling company Scale AI last month. As part of the deal, he also brought in Scale AI's co-founder Alexandr Wang to lead Meta's superintelligence unit as chief AI officer. 

Earlier this month, Wang wrote on X that he will be working alongside former GitHub CEO Nat Friedman. Wang also listed the names of other employees hired by Meta from rival companies OpenAI and DeepMind.

Later, Meta also roped in Safe Intelligence's co-founder and CEO Daniel Gross. This prompted Ilya Sutskever to formally step into the role of CEO at Safe Intelligence, which he had launched last year after leaving OpenAI.

OpenAI had cried foul against Meta's poaching activities with Mark Chen its chief research officer likening Meta's action to a burglary when Chen said: “someone has broken into our home and stolen something.”