Elon Musk’s Optimus robotics program now teeters on shaky ground following the abrupt exit of its engineering chief.

On Friday, Milan Kovac, one of the architects behind Musk’s bid to build humanoid helpers, tendered his resignation, effective immediately. Kovac took to X shortly thereafter, calling his departure “the hardest decision of my life” and citing a longing to “spend more time with my family.” A Bloomberg insider confirmed that Ashok Elluswamy, veteran leader of Tesla’s Autopilot teams, will step in as Optimus’s new engineering head.

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This marks a significant leadership shakeup for Musk, who’s been positioning robotics as Tesla’s next big frontier. Optimus, however, hasn’t exactly wowed since its 2022 debut, when a prototype was famously wheeled out by humans, barely functional. Fast-forward to October: sleek demos in Los Angeles featured Optimus units slinging drinks and charming investors. But much of the “wow” factor was tempered by reports that some tasks were remotely operated by humans.

Musk envisions Optimus robots roaming our homes, tackling chores from laundry to lawn care. He’s hinted that, at scale, each unit could retail in the $20,000–$30,000 range. But with Kovac’s sudden departure, the path from concept to household appliance seems a little more uncertain.