Fan-out / fan-in
A workflow pattern where a step splits work into parallel branches (fan-out) and a later step waits for all of them to finish and combines the results (fan-in).
In more detail
Fan-out is the point where a workflow splits a task into multiple parallel branches, processing many records at once, querying several sources simultaneously, running the same step across a list. Fan-in is the reciprocal: a step that waits for all the parallel branches to finish and merges their results before the workflow continues.
The pattern is how workflows get faster without losing correctness. Independent work runs concurrently rather than one item at a time, and the fan-in barrier ensures the workflow does not proceed until every branch is done. It is the practical mechanism behind parallel processing in an orchestrated flow.
Where this shows up at Ceven
Fan-out and fan-in are how Ceven runs work in parallel where a process allows it, such as gathering from many sources at once during research, then combining the results into a single output. The parallelism is handled by the orchestration, so a workflow you describe in plain language completes faster without you managing the concurrency.