Fan-Out / Integrate
Independent subtasks dispatch to parallel workers (subagents), each with a scoped brief; results return to an integrator that reconciles, checks, and assembles them.
When to use
Breadth-heavy work: multi-file searches, parallel feature tracks, batch content production.
Steps
| Step | What happens | Verification |
|---|---|---|
| Partition | Split work into subtasks that share no mutable state. | Independence test: no subtask reads what another writes. |
| Dispatch | Send each worker a self-contained brief with its own success criterion. | Brief sufficient without the orchestrator's context. |
| Integrate | Collect results, verify each against its criterion, reconcile conflicts, assemble. | Integrator checks every result; unchecked parallel work is parallel risk. |
Specification
| Verification method | Per-worker criteria at integration time; the integrator is a reviewer, not a stapler. |
|---|---|
| Recovery behavior | re-dispatch-failed-subtasks |
| Observability | Worker briefs, results, and integration decisions. |
| Inputs | Partitionable task, Worker capacity |
| Outputs | Assembled result, Per-worker verification record |
| Risk level / maturity | medium / established |
Failure modes
- Misjudged independence produces conflicting edits
- Integrator rubber-stamps worker claims
- Partition overhead exceeds parallel gains on small tasks
Assessment
Parallelism is a multiplier on whatever verification you have, including none. The integrator-as-reviewer rule is what keeps fan-out from being fan-out-and-hope.