The quick brief.
- Map the business event and the systems responsible for each step.
- Make the interface contract and access rules explicit.
- Design failure handling, testing, and support alongside the successful path.
Map the business handoff before the interface
An integration request may sound simple: send a customer update to another application or create an order when a deal is approved. The details matter. Which system owns the record? What counts as approval? What should happen if the destination already has a different version?
Draw the workflow with the people who operate it. Identify the event that starts the exchange, the information required, and the point at which the business considers the task complete. This helps prevent a technically successful request from being mistaken for a completed business process.
Define a contract both sides can understand
The OpenAPI Specification describes a standard, language-independent way to document HTTP APIs. A shared interface description can make operations, inputs, responses, and security requirements clearer to the teams implementing and consuming an API.
Whatever documentation approach the project uses, agree on the meaning of the fields as well as their format. Include examples, validation rules, error responses, and the way changes will be communicated. An interface contract should help a receiving team understand what it can rely on.
Technical references: OpenAPI Initiative — The OpenAPI Specification (opens in a new tab)
Review access and failure behavior early
Authentication and authorization deserve separate attention. OWASP’s API Security guidance identifies broken object-level authorization as an important API risk. A caller’s identity does not by itself establish that the caller may access or modify every referenced record.
Alongside access rules, discuss timeouts, duplicate messages, partial completion, and unavailable dependencies. Decide which actions can be retried safely and how the team will investigate a failed handoff. These decisions should be reviewed for the specific interface and business operation.
- Define which identities may perform each operation.
- Check access to the particular records involved.
- Agree on timeout, retry, and duplicate-handling behavior.
- Record an escalation path for incomplete business transactions.
Technical references: OWASP — API Security Top 10 (opens in a new tab)
Test the workflow and make it observable
Exercise the integration beyond a single successful request. Include invalid inputs, changed records, repeated events, unavailable systems, and the permissions used by different callers. Validate the business result with the people who depend on the handoff.
Plan how the support team will follow an exchange across systems without exposing sensitive payloads unnecessarily. Logs, metrics, and traces can support investigation; OpenTelemetry’s observability guidance provides useful context for these different signals. The project should decide which information is necessary and who may access it.
Technical references: OpenTelemetry — Observability primer (opens in a new tab)
Build one complete and supportable exchange
Select one handoff with a clear owner and an identifiable outcome. Agree on the contract, access model, validation, failure paths, and support responsibilities before expanding into more interfaces. That creates a useful pattern for the next connection.
DUB Consulting helps with interface discovery, API contracts, integration architecture, authentication and error-handling design, testing, and operational documentation. The goal is an exchange that fits the business process and remains understandable after delivery.