Construct a Sequence Diagram That Includes API Calls 350-901 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A team is creating a sequence diagram to document how a client interacts with a REST API. The diagram shows the client, the API gateway, and the backend service as lifelines. The client sends a request to the gateway, which forwards it to the backend. The backend processes it and returns a response to the gateway, which then returns it to the client. Which element is essential to show the period during which the backend service is actively processing the request?

   • AA note attached to the gateway lifeline
   • BA state invariant on the client lifeline
   • CAn activation bar on the backend service lifeline
   • DA combined fragment labeled 'alt'
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2. 2expert · medium

   A developer is modeling an API call where the client sends a request and the server processes it. The server then sends a response back to the client. The developer wants to show that the server is actively processing during the entire time between receiving the request and sending the response. Which notation should be used?

   • AA note on the server lifeline, explaining it is processing
   • BA combined fragment labeled 'processing' around the server's messages
   • CA state invariant on the server lifeline, indicating it is processing
   • DAn activation bar on the server lifeline, spanning from the request to the response
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4. 3expert · hard

   A team is creating a sequence diagram for a complex workflow that involves multiple API calls. The diagram is becoming cluttered with too many lifelines and messages. The team wants to simplify it while still showing the essential interactions. Which approach is most appropriate?

   • AGroup related lifelines into a single lifeline with a note explaining the grouping
   • BReplace the sequence diagram with a use case diagram
   • CUse a single lifeline for all system components and show only the external API calls
   • DRemove all return messages and only show the request messages
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5. 4expert · medium

   A developer is documenting an API that supports both synchronous and asynchronous operations. For synchronous operations, the client waits for a response. For asynchronous operations, the client receives a 202 Accepted and later receives a callback. The developer wants to show both patterns in one sequence diagram. How should the asynchronous callback be represented?

   • AAs a note attached to the client lifeline, describing the callback
   • BAs a message from the client to the server, labeled 'callback'
   • CAs a return message on the same arrow as the 202 Accepted response
   • DAs a separate message from the server to the client, occurring after the initial request and response
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6. 5expert · medium

   A team is creating a sequence diagram to document a third-party API integration. The diagram shows the client, the company's backend, and the third-party API. The client calls the backend, which then calls the third-party API. The third-party API returns a response to the backend, which then returns a response to the client. The team wants to highlight that the third-party API is external to the company's system. How should this be represented?

   • AAdd a note to the third-party API lifeline explaining it is external
   • BUse a different color for the third-party API lifeline
   • CUse a combined fragment labeled 'external' around the third-party API calls
   • DPlace the third-party API lifeline on the right side of the diagram and label it as an external system
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