Designing Sequence Diagrams for API Orchestration

Know what happens when the user presses a button

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Sequence diagrams help visualize what happens when an action occurs — such as when a user presses a button on your app. They are commonly used by technical and business teams to architect solutions, understand requirements for new system integration and/or to document an existing process.

While sequence diagrams can be applied to various scenarios, in this article, we will go over how to design sequence diagrams for API orchestration. You’ll need to be familiar with APIs or application program interfaces, which basically enable different apps to communicate with each other via an exchange of requests and responses. I’ve written a separate blog going over how to read API documentation here. API orchestration is the act of chaining these separate calls together to solve a problem.

Begin with the Use Case

What problem are you trying to solve? This is the first question that you should ask when designing a sequence diagram. API orchestration begins with the use case, followed by the available APIs — and not the other way around.