Elon Musk promised to release a new version of Grok every two weeks, but the three core team members building the model all resigned within a week.

AIMPACT News, May 14 (UTC+8), according to Beating Monitoring by Dongcha, over the past week, three key technical leaders directly involved in building the Grok model at xAI have announced their departure. Unlike previous departures of co-founders and senior executives, these three individuals are the actual heads of the core product lines of search post-training, pre-training, and speech. Their collective exit will directly impact the iteration capability of Grok’s next-generation models. Tianyi Zhang confirmed his departure today on X. He was the head of the search and factual post-training team, previously serving as a machine learning engineering manager at Apple for five years. He led the team to reduce the factual error rate of Grok’s real-time mode by 70% to 80%, helping Grok 4.20 top the Search Arena blind test rankings immediately after launch. This search capability has also been integrated into Tesla’s vehicle system. Juntang Zhuang announced on May 9 that he had left earlier this year. He deeply participated in pre-training since Grok 2, later becoming the head of the pre-training team, leading the training infrastructure and core formulas for the entire Grok 4 series models. Before joining xAI, he worked at OpenAI for two years, being a core contributor to GPT-4o and the inventor of the GPT-4 Turbo 128k long-context algorithm. David Haxton confirmed his departure on May 10, having previously built Grok’s speech agent, real-time thinking speech, and voice cloning functions from scratch. In Sierra AI’s τ-Voice speech agent benchmark test, the Grok Voice team he led is currently ranked first, ahead of OpenAI and Google. The timing of these departures is particularly conspicuous. The publicly available Grok 4.3 is still an intermediate training version with 0.5T parameters. Elon Musk said on April 18 that the true flagship with 1T parameters “is about 5 days away from initial training completion,” and the next day clarified that Grok 4.4 = 1T, expected to be released in early May; Grok 4.5 = 1.5T, aiming for delivery by the end of May, claiming the model factory has been operational, with a new base model released every two weeks thereafter. Now it is mid-May, and Grok 4.4 has yet to appear, while the core personnel responsible for building these models are accelerating their departure. xAI is experiencing a systematic talent drain from co-founders to the core model team. (Source: BlockBeats)