  The Rubin Observatory's Data Butler is designed to allow data file location
and file formats to be abstracted away from the people writing the science
pipeline algorithms. The Butler works in conjunction with the workflow graph
builder to allow pipelines to be constructed from the algorithmic tasks. These
pipelines can be executed at scale using object stores and multi-node clusters,
or on a laptop using a local file system. The Butler and pipeline system are
now in daily use during Rubin construction and early operations.
