One AI agent does not need to solve every part of a problem alone.
When a problem benefits from different perspectives, I use Fan-out / Fan-in.
Fan-out
Fan-out splits the problem into independent branches.
For example, when reviewing a technical proposal:
One branch reviews the architecture.
One reviews security risks.
One evaluates the user impact.
Fan-in
Fan-in then compares the findings against a shared goal, removes duplication, resolves conflicts, and produces one recommendation.
That last step matters.
Without synthesis, you do not have a result. You only have several separate opinions.
The pattern in a larger workflow
The key rule is simple:
Can the branches work without waiting for each other? → Fan-out
Bring their findings together into one result → Fan-in
The pattern can sit inside a larger workflow:
Plan → Fan-out → Work independently → Fan-in → Verify
The value is not in creating more branches.
It is in combining independent perspectives into one stronger result.