System Integration Planning: APIs, Data and Ownership

Suivez un échange de bout en bout.

Choisissez un échange représentatif, comme une commande passant d'un site internet vers une application interne. Répertoriez le système d'envoi, le système de réception, les champs et le déclencheur. Décidez quel système possède chaque valeur. Si deux systèmes peuvent mettre à jour le même enregistrement, documentez la manière dont les mises à jour conflictuelles seront traitées avant de créer l'interface.

Conception pour messages retardés et répétés.

Une intégration peut recevoir deux fois la même requête ou perdre une réponse une fois que le récepteur a terminé son travail. Discutez des identifiants, des tentatives et du rapprochement avec l'équipe de mise en œuvre. Définissez comment les utilisateurs voient un échange en attente ou en échec, et qui peut le corriger en toute sécurité sans créer de dossiers commerciaux en double.

Rendre l'interface révisable.

Enregistrez des exemples d'entrées acceptées et rejetées, de réponses attendues et d'exigences d'accès. Incluez un processus de changement afin qu’un système ne puisse pas briser l’autre en silence. Examinez le contrat avec les deux propriétaires et testez les échecs des représentants avant de considérer l'intégration prête à être utilisée de manière opérationnelle.

Walk through the life of an exchanged record

Choose one record, such as an order, and follow its creation, update, cancellation and correction. At every boundary, identify the sending system, receiving system and source of truth. Confirm the actual interface available rather than assuming that an application exposes the data you need.

Review authentication, field meanings, identifiers and expected timing with both owners. Test a duplicate message, a delayed update and an unavailable destination. Decide how to distinguish a rejected request from an uncertain outcome. Arrange reconciliation so the operating team can find records that disagree after an interruption. These decisions should be captured before implementation begins.

An interface contract planning sheet

This is a discussion template, not a substitute for the technical contract. Attach the relevant API specification or file format after the owners agree the behaviour.

• Purpose and direction: why the exchange occurs and which system initiates it.
• Record identity: stable identifiers, field definitions and ownership of each value.
• Trigger and timing: event, schedule, expected delay and ordering assumptions.
• Access and limits: authentication, permissions and constraints confirmed by the provider.
• Failure handling: timeouts, duplicates, retries, rejection reasons and human escalation.
• Verification: test examples, reconciliation checks, versioning and named support owners.

Do not equate a response with a completed business action

A successful technical response may acknowledge receipt without confirming that a downstream process finished. Agree what each status means and how completion is checked. Conversely, a timeout may leave an uncertain result, so retrying a consequential action without checking can create duplication.

Avoid relying on field names alone. Two systems may use the same label for different concepts. Keep mappings and interface changes visible to both teams, including who approves a breaking change.

Should an integration be real time?

Choose timing around the business need and the capabilities of the connected systems. A scheduled exchange may be sufficient for some tasks; others need an event-driven flow. Document the acceptable delay and recovery approach before choosing the implementation pattern.

ILLUSTRATIVE PLANNING EXAMPLE

Example: connecting orders and inventory

An order system sends confirmed purchases to inventory. Decide which system owns stock counts, when a reservation occurs and how cancellations reverse it. Ask what happens when the same message arrives twice or inventory is temporarily unavailable. Assign an owner to each interface and agree representative integration tests.

Create an interface sheet covering fields, triggers, permissions, duplicate handling and recovery. Confirm assumptions with both system owners before estimating the connection.

FURTHER READING

Official resources to explore

Explore the related official guidance below. The templates and examples are practical starting points to adapt to your own project.

• MDN: overview of HTTP