A full inventory of your source data — schemas, dependencies, volumes, and the edge cases no one remembers to mention.
Row-level reconciliation, checksums, and validation suites. You know every record made it and nothing was quietly dropped.
Cutover plans that minimize business disruption — dual-write, replication, or scheduled windows, matched to your risk tolerance.
History, audit logs, and attachments migrate with the transactional data. Nothing gets left behind on the old system.