03 / Agent roles
Separate the search from the check
The division of work can matter more than the number of agents.
What DoorDash reports
DoorDash first used specialist reviewers. They found local errors but missed problems across system boundaries.
The next design used two reviewers with broader context. Each had too much to check, and some findings were lost.
The third design added a scout. It identifies possible issues. Two reviewers then investigate those issues. [1]
“The lead scout's job isn't to verify anything.”
DoorDash, on the scout’s role. [1]
Narrow context
Too much to check
Find leads, then verify
Our observation
Each role needs a clear result
A possible issue and a verified issue are different results. Separate roles can make that difference explicit.
This design may help when a broad search precedes a detailed check. It may add unnecessary work when one agent can complete both steps.
This is one team’s report. It does not prove that three agents are better than two.
A question for your buildWhat must each agent produce before the next agent can use its result?
Source
- DoorDash: How we built an AI code reviewerThe “How we got here” section describes all three designs.