Reschedule a visit without releasing its old slot prematurely
A reschedule releases the old appointment before reserving the new one, leaving customers unbooked if the target is taken.
- Focused work estimate
- 4h + prerequisites
- Priority in the scenario
- Medium
- Engineering practice
- Transactions · Idempotency
Estimated field mix
- Database engineering60%
- Backend40%
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 equipment service books maintenance visits. Expiring checkout holds and reschedules occasionally double-book a technician.
Setup prerequisites
- Build synthetic technicians, slots and booking records.
- Use an injectable clock and separate clients for concurrency probes.
Preceding work
Complete these dependencies, or supply their agreed outputs before taking this ticket.
Acceptance criteria
- Reserve the target and release the source atomically.
- Retain the original appointment on target conflict.
- A retried successful command returns the same replacement.
Implementation constraints
- Keep both slot locks in a documented stable order.
Verification to include
- Move a visit and inspect one confirmed appointment.
- Race for the target and verify the losing reschedule keeps its source.
Deliverables
- Reschedule command and transaction tests
Rollout and recovery
Enable for synthetic bookings; disable rescheduling while ordinary reads continue.
Value of the work
For the engineer: Practice resource allocation, interval conflicts and durable workflows.
For the team: Review scheduling correctness and recovery before exposing scarce capacity.
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.