Abstract: Methods, systems, and computer program products for migrating a system from a legacy platform to a replacement platform. Input data is provided to the legacy and replacement platforms during a dual-run phase of migration, and documents in a legacy database and a replacement database updated independently based thereon. In response to a document in the replacement database being updated, an image of the document is captured in an envelope to maintain a history of the document. During the dual-run phase, documents may be migrated from the legacy database to the replacement database, and captured as images in envelopes in the replacement database. Images of migrated documents may be compared to images of native documents to validate the replacement platform. Migrated documents may be cleansed, and native documents may be filtered or merged with migrated documents based on the comparison. Migrated or native documents may then be selected as master documents.