Scenario-Based Questions

Definition

Interview questions that present a complex, real-world business problem and ask you to design the API architecture to solve it.

Explain Like I'm New

There is no single 'right' answer. The interviewer wants to hear your thought process. They want to see if you can balance performance, security, and scalability.

Real World Example

Scenario: 'We are building a live sports scoreboard for the Super Bowl. Millions of users will have the app open simultaneously. How do you deliver the live score?'

Common Use Cases

•System Design Interviews

Interactive Example

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Interview Questions

basic

Scenario: You need to upload a 5 Gigabyte video file to an API. How do you handle it?

intermediate

Scenario: Your frontend needs to know when a background video rendering task finishes. Do you use Polling or WebSockets?

Flash Cards

Question

Upload 5GB file?

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Answer

You do NOT send it through your Node.js API server, as that will block the server and run out of memory. You should request a 'Pre-signed URL' from the backend, and have the frontend upload the massive file directly to AWS S3, bypassing your backend entirely.

Question

Polling or WebSockets?

Click to reveal answer

Answer

Neither. Video rendering takes minutes or hours. Keeping a WebSocket open that long is inefficient and fragile on mobile networks. Short Polling destroys the server. The best approach is Long Polling, or Server-Sent Events (SSE), or simply using Push Notifications if it's a mobile app.