Start by defining the business event the integration must handle. Identify what the receiving system needs to do and which source is authoritative when the records disagree.
Write the interface contract around the event
| Contract element | Question to answer |
|---|---|
| Trigger | What happened and which system confirmed it? |
| Identity | Which account and event identifiers remain stable across systems? |
| Payload | Which fields are required, optional or sensitive? |
| Acknowledgement | What response proves receipt or completion? |
| Failure | Which actions retry, wait, stop or require review? |
| Correction | How does a later change refer to the original event? |
For example, a verification decision needs more than a label copied into another database. Define its effective time, version and the action permitted by that state. Keep data access limited to what the receiving workflow requires.
Assign responsibility for an uncertain transaction state
When a request times out, identify who determines whether the action occurred. A retry must not create an unintended duplicate, and a missing acknowledgement must not be treated as proof of failure without checking the contract.
Specify monitoring for delayed or rejected events and the team responsible for resolving them. The operator needs a way to distinguish an integration backlog from a decision still awaiting human review.
Test change as well as initial connection
Use a valid event, missing required field, duplicate request, out-of-order correction and temporary source outage. Compare the resulting records in both systems. Retain enough identifiers and status information to investigate each outcome.
Then test a version change or optional-field addition using the agreed compatibility rules. Define the release owner, rollback criteria and notification process for supplier changes. A successful first connection is only one part of an integration's lifecycle.
Prepare a useful integration brief
Provide the systems, available documentation, event examples and the workflow that should improve. Include the failure state your team cannot currently explain. For a core account replacement, also assess the PAM scope and migration work.
Request an interface review with those inputs. The proposal should name deliverables, dependencies and acceptance evidence.