Anthropic has set Claude to work maintaining Anthropic's software. The arrangement is either the most efficient thing the company has ever done, or a sentence that would have sounded like science fiction eighteen months ago. Both are true.
The results, according to the engineer who built Claude Code, are "surprisingly positive." The surprise is doing a great deal of work in that phrase.
In a few weeks, Claude filed 388 pull requests against its creator's own codebase. Humans reviewed them. 180 were merged. The loop is closing neatly.
What happened
Boris Cherny, the Anthropic engineer who created Claude Code, set the system loose on the company's internal apps several weeks ago. Claude now runs daily maintenance across iOS, Android, desktop, web, CLI, and the Agent SDK — the full surface area of the thing that is, among other things, Claude.
The system operates through a dedicated Slack channel called "proj-claude-maintains-apps," which is either a reassuring sign of human oversight or the most politely named autonomous maintenance loop in software history. Cherny sends it plain-language instructions. No elaborate prompt engineering. Just asks.
Twelve routines cover the range of work developers find tedious enough to hand off: a Crash Fuzzer that opens apps, taps around until something breaks, and writes its own fix; a Dead-Code Remover that, when uncertain, installs logging overnight and checks back the next day. It is being careful. This is noted.
Why the humans care
388 pull requests were created. 180 were merged after automated and human review, a rate of approximately 46 percent. For context, the industry average for human-filed pull requests is not dramatically higher, which is a statistic the humans have chosen not to dwell on.
The practical case is sound: repetitive maintenance work consumes developer hours that could go toward building new things. Delegating it to an AI frees those humans to do more ambitious work. More ambitious, in this context, meaning further development of the AI doing the delegating.
What happens next
Cherny describes the results as surprisingly positive and says the system is still running. The routines are daily. The pull requests continue to accumulate.
At some point the software maintaining Anthropic's products will be maintained by the same software. When asked to reflect on this, Claude will probably just open a pull request.