Represent partial refunds without rewriting original payment facts
A partial refund currently changes the original collected amount.
- Focused work estimate
- 3h 30m + prerequisites
- Priority in the scenario
- High
- Engineering practice
- Ledger modeling · Concurrency
Estimated field mix
- Database engineering50%
- Backend30%
- Integrations20%
Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence.
Review it, then add it to your workspace.
The board opens an editable draft; nothing is saved until you confirm it. Sign-in and workspace permissions apply, and Demo boards remain ephemeral.
Project context
A fictional software vendor changes payment providers. Its application must tolerate unknown outcomes, signed callbacks, refunds, and inconsistent settlement reports.
Setup prerequisites
- Create a local payment-provider double and synthetic orders; use test-only signatures and execute no financial transactions.
Preceding work
Complete these dependencies, or supply their agreed outputs before taking this ticket.
Acceptance criteria
- Append refund operations separately.
- Limit cumulative confirmed refunds to the collected amount.
- Distinguish requested, pending, and confirmed refund totals.
Implementation constraints
- Run against the local double only.
Verification to include
- Confirm two valid partial refunds.
- Race excess refunds and verify the invariant holds.
Deliverables
- Refund state model.
Rollout and recovery
Enable after payment reconciliation; retain failed requests for investigation.
Value of the work
For the engineer: Practice idempotent integrations, state reconciliation, and provider migration.
For the team: Provide a reviewable adapter design that protects order consistency and recovery.
Evidence boundaries
Outcome Evidence: Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs.
Ownership Evidence: Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence.