Design a useful data handoff

Two applications can both accept a CSV and still disagree about dates, currency or record identity. A data handoff needs a shared contract. Start with a small example containing normal records, missing fields and one deliberate error.

Work through it

1. Define stable record identifiers, required fields, accepted formats and the meaning of blank values. State the timezone and currency where relevant.
2. Decide how updates, duplicates and deletions are represented. Make a rejected record visible with enough detail for a person to correct it.
3. Test a round trip: export from the source, import to the destination, then compare important fields and counts. Keep the original export until reconciliation is complete.

Check your result

• Field definitions are documented.
• Rejected records are recoverable.
• The receiving team can reconcile counts and key values.