An integration is not just a connection between two APIs. It changes the experience of the people who rely on those systems to do their work.
The important questions are usually at the handoff. What happens when information is missing? Who can correct it? How will someone know the sync has completed? What should they do when it has not?
Design the exceptions
The happy path is rarely the hard part. A strong integration makes the edge cases visible and gives people a practical way to resolve them. Good status messages, sensible defaults and a clear history can turn a fragile connection into a trusted part of the workflow.
Give the system an owner
Every connection needs someone who understands its purpose and can make decisions when the business changes. Document the intent alongside the technical details. Future teams should know not only how it works, but why it exists.