Use this skill when an Airflow DAG uses dynamic task mapping — task.expand(param=[...]), task.expand(param=XComArg(...)), task.partial(...).expand(...), or expand_kwargs() (Airflow 2.3+) — to create a variable number of task instances at runtime from a list, dict, or an upstream task's output. Triggers: any DAG using .expand(, .partial(, expand_kwargs(, map_index, or task mapping over a list of files/pages/config entries/API results. Orchestra's equivalent is a matrix task group (TaskGroupModel.matrix), not a plain loop — read this before converting any mapped Airflow task to Orchestra YAML.