An integration becomes a product dependency when customers can no longer complete an important task without it. At that point, maintaining the connection is part of the product promise, not a one-time implementation detail. Changes in permissions, data shape, delivery behavior or supplier availability can affect the customer even when the product’s own interface has not changed.
This guide proposes a dependency review for SaaS teams. It does not assert that any named project currently relies on a particular vendor.
Identify what the customer depends on
List the tasks supported by the integration and what happens if it becomes unavailable. Some products can continue with a recent snapshot; others must stop because stale information would be misleading. The fallback should follow the task’s risk and freshness requirement.
Write which system is authoritative for each important field. If both systems can change the same value, define conflict handling. Otherwise a successful synchronization can still produce an incorrect business state.
Keep a dependency register
| Area | Information to preserve |
|---|---|
| Capability | Which customer task needs the integration |
| Contract | API version, required fields and supported behavior |
| Access | Granted scopes, account owner and renewal process |
| Reliability | Detection, retry and reconciliation approach |
| Cost | Usage drivers and commercial limits |
| Change | Deprecation notices and review owner |
| Exit | Export, replacement or graceful shutdown path |
The register should be short enough to maintain. Its purpose is to avoid rediscovering ownership and assumptions during an incident.
Treat event delivery as a contract
Do not assume every notification arrives once, in the desired order and with no delay. Use the provider’s documented behavior. Shopify, for example, documents possible duplicate webhook deliveries and recommends idempotent processing, with delivery identifiers available for duplicate detection. Shopify’s delivery-verification guide is the primary reference for that integration.
The product still needs to know whether its local state agrees with the authoritative source. A reconciliation process can detect gaps that individual event handling misses. Receiving a webhook successfully is not the same as completing the customer’s downstream task.
Design degradation honestly
When the dependency fails, show which information is stale or which operation is unavailable. Do not continue displaying an apparently current result if its source has stopped updating. Let the user understand whether they can retry, wait or use another supported path.
A partial service can be preferable to total failure when its limits are clear. But a fallback that silently omits essential data can be more harmful than an explicit stop. The data-quality SLA guide helps connect freshness and completeness to decisions.
Test changes before customers discover them
Maintain contract tests or representative integration checks around critical behavior. Review supplier notices and permission changes through an assigned owner. A dependency that worked at launch should not be assumed to remain compatible indefinitely.
Include recovery scenarios: expired access, duplicate delivery, delayed response, partial update and changed field values. Preserve enough diagnostic evidence to distinguish a product defect from a supplier failure without making the customer perform that investigation.
Revisit the ownership decision
Growing dependence may justify a better adapter, another provider, a narrower promise or building part of the capability internally. The build-versus-integrate guide provides the comparison. Replacement also has cost and risk, so dissatisfaction alone is not a complete migration plan.
A healthy integration strategy recognizes that the external system is part of the user’s experience. It assigns ownership to that relationship, makes failures understandable and keeps a practical route for change when the dependency no longer serves the product.