CS API Development & Integration 4

Question 1

An API supports conditional requests. A client sends If-None-Match with a previously received ETag, and the resource is unchanged. What should the server return?

Accepted Answer

304 Not Modified with no body

Answer

When the ETag still matches, the server returns 304 Not Modified so the client can reuse its cached copy.

Question 2

Which pagination strategy scales best for very large, frequently changing datasets like an activity feed?

Accepted Answer

Cursor-based (keyset) pagination

Answer

Cursor-based pagination avoids the skipped or duplicated rows and slow deep offsets that plague offset pagination on changing data.

Question 3

A third-party integration only needs read access to a user's calendar. Which OAuth 2.0 concept enforces this least-privilege limitation?

Accepted Answer

Scopes

Answer

Scopes restrict what an access token is allowed to do, such as calendar.read only.

Question 4

During a rolling deploy, an API gateway sends requests to instances that fail their health checks. What is the primary purpose of such health-check endpoints?

Accepted Answer

To let the load balancer route traffic only to instances able to serve requests

Answer

Health checks let load balancers and orchestrators detect unhealthy instances and remove them from rotation.

Question 5

Which scenario is a textbook use case for webhooks rather than client polling?

Accepted Answer

A payment provider notifying your server the moment a charge succeeds

Answer

Webhooks push event notifications to your endpoint as they happen, eliminating wasteful repeated polling.

(CS) Computer Science Practice Test

(CS) Computer Science Practice Test

CS API Development & Integration 4