Some of the FSD and Cybercab features that show up in a software update aren’t written by a person sitting down and typing code line by line anymore. Tesla says its AI model Grok is now doing real engineering work on the company’s own software, running overnight while nobody’s watching.
What Tesla actually said
Tesla CEO Elon Musk posted on X that “Grok 4.7 [is] doing real engineering work at Tesla,” according to reporting from Tesla North. Yun-Ta Tsai, a senior staff engineer on Tesla’s AI team, backed that up with specifics of his own: Grok teams spent weeks tuning a framework called the “Build harness” that lets the model act as an autonomous overnight coding agent, with improvements to self-validation and longer-running monitoring of its own work. Tsai said he’s personally shipped FSD and Cybercab features this way, though he didn’t say which ones.
What’s still unconfirmed
Neither Musk nor Tsai named a specific feature that shipped through this process, and Tesla hasn’t published any data comparing how much faster this makes development versus a human engineer writing and testing the same code. There’s no announced timeline for expanding it, either. Treat this as Tesla confirming the process exists, not a preview of what’s coming next.
Seeing it in the car
Dirty Tesla’s channel caught a related moment worth watching: a Cybercab getting a flat tire in the wild, alongside a look at what Grok’s growing role in FSD development means for the cars on the road today. The video is from September 29, 2026.
This video shows one creator’s hands-on look at the Cybercab and Tesla’s AI-assisted development — it’s illustrative, not a source for the claims above. For those, see the reporting linked in this article.
Photo by Negative Space.