Ownerless Code

We used to review code that somebody understood. The author arrived with a mental model; the reviewer attacked it, tested its edges, and found what it missed. Agent-written code can arrive before any human has formed that model at all. The reviewer is no longer checking an explanation. They are being asked to create the first one, while parachuting into a diff they did not write. The bottleneck is people who understand the code well enough to own it; reviewer time is secondary.

The diff can tell you what changed. It cannot tell you what you no longer know. The code this change depends on may have been rewritten two pull requests ago, and nobody in the room carries the provenance of either decision. What looks like a local modification is standing on a system whose shape moved without a mental model forming around it. The reviewer has to recover both the blast radius of this change and the understanding that was never produced with the changes before it.

That reconstruction has a shape: open the component, jump to the custom hook, then the service, then the API client. By the time you reach the behavior, you have lost the line that made you look for it. You return to the diff, reconstruct the question, and begin again. Every jump consumes a little of the context that justified making it. The reviewer repeatedly evicts the problem from working memory to load its explanation.

Volume still matters. Agent-written code arrives in walls, and locality does not make a five-hundred-line pull request smaller. The pain of a large review is line count multiplied by cost per line. Five hundred lines whose behavior stays local can be read straight through, stopping where something looks wrong. When every other line sends you out of the diff, that is impossible. Brutalism makes that wall readable.

Call it single-pass legibility: a reviewer should be able to read the pull request once and see what changed, what it can affect, and where doubt begins. One reading cannot prove a non-trivial change correct. Legibility makes the boundary of further investigation visible. Hiding the need for more context is the failure.

Legibility makes ownership possible; a human still has to supply it. Ownerless code is the problem. A human can write code nobody understands; an agent can write code a human fully owns. Ownership means somebody can explain the change, see its consequences, and answer for it before asking another person to approve it. A reviewer can attack a mental model. They should not have to invent one on the author’s behalf.

Before asking for review, read your own diff without reopening the conversation that generated it. Can you see what changed, what it can affect, and where the unknowns begin? If you cannot recover the blast radius from the code you are submitting, the reviewer will have to recover it for you. The author gets one first pass too.