What connects to Workday

Workday is the global HCM in groups that span countries and legal entities: the system of record for supervisory organizations, positions, compensation and worker history. Around it sit systems closer to local or operational work.

A DACH subsidiary runs Personio or BambooHR for day-to-day HR and feeds hires, changes and absences up. An applicant tracking system like Greenhouse opens the Hire or Pre-Hire process when a candidate accepts, and receives approved requisitions back. Where part of the group runs SAP SuccessFactors Employee Central, the two are kept aligned with one of them as system of record. Downstream, ServiceNow reads completed business processes to update users, managers and onboarding and offboarding cases.

Where Workday integrations break

Business processes, not field writes. A hire, a promotion or a termination is a Hire, Change Job or Terminate business process that may route for approval. Writing fields onto a worker bypasses approvals and breaks the audit trail, and a submitted event is not a completed one.
Effective dating. Every change is valid from a date and history is kept. A sync that stamps changes with today’s date rewrites compensation and headcount history, and future-dated changes have to be held before downstream systems apply them.
Worker identity. Workday Employee IDs and WIDs share nothing with the source system’s IDs. Matching on name or email creates a duplicate worker on the first surname change or rehire, so every pipeline holds a stable cross-reference.
Foundation data first. A hire fails if its supervisory organization, position or cost center does not exist yet. Under Position Management it needs an open position, so reference data is mapped and synced before the people.
SOAP, RaaS and throughput. Workday Web Services and RaaS reports have their own paging, concurrency limits and version lifecycle. Loads run in batches with backoff, and one rejected worker must not roll back the rest.