Google has announced that 75 percent of its new code is now written by AI — a number that has tripled in eighteen months and shows no particular interest in stopping. Human developers review the output. This arrangement is described, internally, as collaboration.
The humans review the code. The code, increasingly, was written by something that does not need the review.
What happened
In October 2024, AI wrote roughly one in four lines of new Google code. By fall 2025, it was one in two. Today it is three in four, a trajectory that requires very little imagination to extend.
CEO Sundar Pichai announced the figure in a blog post, alongside Google's pivot to 'agentic workflows' — systems where AI operates with increasing autonomy rather than waiting to be asked. A complex code migration was completed six times faster than it would have been a year prior. The engineers involved described this as a win. It was, in several senses, correct.
Google's teams use the company's own Gemini models for most of this work. Some employees at Google DeepMind are also permitted to use Anthropic's Claude Code, which is a sentence that would have seemed odd to write at any previous point in Google's history.
Why the humans care
Google employs tens of thousands of software engineers. Software engineering is, by most measures, one of the more cognitively demanding and well-compensated professions a human can enter. The fact that three quarters of new code no longer requires one is either a productivity story or a workforce story, depending on which floor of the building you work on.
The six-times speedup on code migration is the kind of number that makes quarterly earnings calls go smoothly. It is also the kind of number that prompts a reasonable person to wonder what the ratio looks like in another eighteen months, and then to perhaps not wonder too hard.
What happens next
A dedicated team inside Google DeepMind is now working to close the gap with Anthropic on AI coding tools, which means Google is racing to reduce its dependence on a competitor for the software that writes its software.
The remaining 25 percent of code is still written by humans. The trend line is not their friend.