News for hackers. Stuff that matters.
Re:Five months treating bugs like patients and coding agents... by ajstorm on Friday October 09, 2026 @11:29AM (#50021962)
Rafi and I, who authored this post, will be hanging out here for any questions people may have.
Re:Five months treating bugs like patients and coding agents... by contingencies on Saturday October 10, 2026 @07:11PM (#50038078)
Which inherent limitations did you recognize in the metaphor before commencing this research?
Re:Five months treating bugs like patients and coding agents... by ajstorm on Saturday October 10, 2026 @09:15PM (#50038844)
One thing that teaching hospitals have is a longer ladder of experience. For example many hospitals have medical students, interns, residents, chief residents, fellows and attendings. One idea we contemplated was to have "treatment" start on the cheapest possible model and see how it ended up, only escalating to more capable/expensive models as necessary. We rejected this idea because we suspected that it would end up in more time/tokens on the capable models to fix any problems.

In the end, medical students learn to become doctors. Cheaper models never learn to become more capable models, so the metaphor is not apt.

Re:Five months treating bugs like patients and coding agents... by Eridrus on Saturday October 10, 2026 @08:00PM (#50038346)
Did you do any ablation studies on what is actually useful vs what happens to just work because these systems can work around whatever people do?

I compare this to OpenAI's symphony prompt which, at a high level, does exactly the same thing outlined here except model selection and doesn't really have the need for roles or hospital metaphors.

Re:Five months treating bugs like patients and coding agents... by ajstorm on Saturday October 10, 2026 @09:08PM (#50038787)
No, we haven't performed any ablation studies yet - it's a good suggestion.

The comparison with OpenAI's Symphony is valid (the two systems do broadly the same thing). One thing that's different about Sinai is that it keeps the code author and reviewer in separate agents with separate context. At the time we built it, we suspected that this would lead to better outcomes, but again, we haven't validated that it does.

I confess that there's a lot more validation we could do with this model but we just haven't found the time. One thing we don't cover in the post is that this is a side project for both of us, so we have less time than we'd like to perform experimentation and validation.

Re:Five months treating bugs like patients and coding agents... by Majromax on Sunday October 11, 2026 @10:52AM (#50043933)
> One thing that's different about Sinai is that it keeps the code author and reviewer in separate agents with separate context. At the time we built it, we suspected that this would lead to better outcomes, but again, we haven't validated that it does.

I use a similar process for a local agent swarm approach (locally hosted Qwen-3.8-27b or Qwen-Flash-Next), used so far for personal-grade projects. Through tool and process accretion, the review stages are told to check both the work and reasoning of the implementation stage, via processing the pi.dev session log.

Through parsing the jsonl log, the reviewer sees the subagent prompt, the tool call sequence, and non-thinking narration along the way. That allows the reviewr to audit the implementer's process (e.g. were tests run?) and spot procedure violations or gross hallucinations. The reviewer also independently runs the test suite, so even a hallucinated pass is caught.

It's relatively expensive both in tokens and time spent running ideally duplicate tests, but the independent workflow has nonetheless caught errors that would very likely have been missed by a same session, same context review.

Re:Five months treating bugs like patients and coding agents... by ArtRichards on Sunday October 11, 2026 @04:39AM (#50040961)
Yes agreed, using a system very similar without the hospital vibe :)
Re:Five months treating bugs like patients and coding agents... by what on Saturday October 10, 2026 @11:21PM (#50039539)
The blog post links to an issue in the Sinai repo, but it’s private or just doesn’t exist?
Re:Five months treating bugs like patients and coding agents... by rafiss on Sunday October 11, 2026 @02:12PM (#50046058)
Sorry about that. The repo is internal to Cockroach Labs for now. It was an issue about adding a progress rollup comment to decomposed parent issues. We’ll get the post updated.
Re:Five months treating bugs like patients and coding agents... by losteric on Saturday October 10, 2026 @11:33PM (#50039590)
are any of these artifacts public and available for inspection/use?
Re:Five months treating bugs like patients and coding agents... by ajstorm on Sunday October 11, 2026 @12:15AM (#50039740)
Not currently, but open sourcing this has been discussed. Stay tuned.
Re:Five months treating bugs like patients and coding agents... by dirtbag__dad on Sunday October 11, 2026 @09:04AM (#50042927)
This, with an extremist take on code quality via linting in ci, is no doubt the future, at least for maintenance and extending the interface kind of work.

1. How does this work with greenfield lifts where the scope and final vision are not yet figured out?

2. Sorry if I missed this in the post, but will you open source this system?

Re:Five months treating bugs like patients and coding agents... by rafiss on Monday October 12, 2026 @01:57PM (#50060220)
The Migration Assistant was mostly a greenfield project and the roadmap was steered directly by feedback we continually received during development. It was built on top of our existing CLI-based tools for migrations, but the web UI and step-by-step wizard with AI assistance was all brand new.

What worked was a human writing the big-picture issue and the hospital decomposing it into a tree of smaller issues, which people could review with more rigor. We also did a few thing that didn't work; in one case we got a bit too over eager in trying to resolve a large slate of issues all at once, and left ourselves with a giant backlog of plans and code to review.

We're discussing internally what can be released in the open, but nothing to share yet.

Re:Five months treating bugs like patients and coding agents... by bethekidyouwant on Sunday October 11, 2026 @11:58AM (#50044655)
How much of this is a snake eating its own tail against vs the control group?
Re:Five months treating bugs like patients and coding agents... by quadrifoliate on Sunday October 11, 2026 @12:26PM (#50044931)
Could you fix a bug in this codebase yourself, without the help of agents?

Maybe trying this would be a good experiment? Say route 10 or 20% of any future issues to the “Chief” to troubleshoot and fix directly, and record those for further work?

Re:Five months treating bugs like patients and coding agents... by rafiss on Monday October 12, 2026 @11:44AM (#50058090)
Yes, the codebase still allows you to make a PR the normal way, and getting another engineer to review. That is, a human could make a PR totally by hand or by steering a Claude session on their machine.

I still find myself taking that approach fairly regularly. For most framework-level changes, or changes to core packages, I think the added scrutiny and deliberation is valuable. But for "leaf" components that don't have many dependents, using the hospital to move rapidly has been invaluable. I also encourage "old-fashioned" PRs for anyone who wants to gain a deeper understanding in a certain area of the code.

I like the control-group idea. It’s close to something we’re already building, where a human can label an issue to opt-in to write the plan or the code themselves. Routing a fixed % of issues that way would give us a baseline we don’t have right now.

Re:Five months treating bugs like patients and coding agents... by quadrifoliate on Tuesday October 13, 2026 @12:05AM (#50066539)
To be clear, when I said "can you", I didn't mean "does the system allow this", more like "are you, the person I am speaking to who is the architect of the system, confident that you could make a fix to this system without the LLM's help?".

> I also encourage "old-fashioned" PRs for anyone who wants to gain a deeper understanding in a certain area of the code.

Yeah, this is kind of what I meant. I think in some future, these are going to be really valuable for maintainers.

Re:Five months treating bugs like patients and coding agents... by anonymid on Tuesday October 13, 2026 @01:00PM (#50074960)
This task seems adjacent to the sort of work agents excel at - there's a language / grammar / specification / examples to follow, verifying correctness mechanically seems like it is possible. So this seems similar to writing a compiler with a specification / test suite available (like the "building a c compiler" thing Anthropic experimented with).

Would you say this is accurate? Have you had challenges generalizing to other sorts of work (you mentioned you're spreading it out to other repos)?