This document discusses an on-demand backfilling solution for Flink pipelines that process incentive programs. It describes a pipeline that evaluates driver incentives based on their status changes. Some incentives are defined retroactively, so an on-demand source was created that can continuously backfill old data. This source emits state changes paired with the applicable incentives from the beginning of each period. It allows a single pipeline to process both new and retroactive incentives without needing separate pipelines. The document also suggests this approach could be generalized into a pipeline template.