Name the authoritative source
For each field or record, identify the system responsible for the correct value. Customer details, stock availability and payment status may come from different sources. Avoid a design where both systems can overwrite the same value without a defined rule.
Confirm the supplier’s actual API, account permissions and limits. A public feature description is not enough to establish that your specific account can read or update the required data.
Make retries safe
A network timeout does not always mean the receiving system rejected the request. If the caller simply repeats a create-order operation, duplicate records can result. Agree identifiers and supported duplicate-prevention behaviour before automating retries.
Webhook integrations also need authenticated notifications and handling for repeated deliveries. Stripe’s webhook documentation, for example, covers signature verification and duplicate events. Use the equivalent rules documented by the provider you actually connect.
Plan operational ownership
Define how a failed update is recorded, who is notified and how the team can safely retry or reconcile it. Logs should identify the affected operation without exposing credentials or unnecessary personal data.
Test unavailable services, rejected data and repeated events alongside the successful path. The goal is an integration your team can investigate and support, with clear boundaries around supplier dependencies.