Challenge your understanding of REST API performance optimization techniques, including caching, request handling, data formatting, and best practices. Enhance your skills by identifying the most efficient strategies for fast and scalable RESTful services.
Which technique helps reduce the amount of data sent in REST API responses when clients only need some fields, for example, excluding unnecessary details from a user profile response?
Explanation: Field filtering allows the client to specify which fields it wants, reducing response size and improving efficiency. Code minification applies to source files like JavaScript, not API data. Header injection refers to adding information in headers and is not related to reducing payload fields. Data batching involves sending multiple requests or items together but does not specifically control the response fields.
What is a recommended way to reduce the number of HTTP requests sent to a REST API, for example, when loading a dashboard with several small data widgets?
Explanation: Batching requests means combining several API calls into one HTTP request, reducing network overhead and improving performance. Increasing the timeout only allows slower responses and does not lessen the number of requests. Changing the base URL has no impact on the request count. Using XML instead of JSON does not inherently affect the number of requests and often increases payload size.
Which HTTP header can indicate that a REST API response may be stored and reused by clients, such as for a product list that changes infrequently?
Explanation: The Cache-Control header tells clients and intermediaries how to cache responses, boosting performance by reducing redundant calls. User-Agent specifies client information and is irrelevant to caching. Origin is included in cross-origin requests for security, not caching. Allow indicates which HTTP methods are supported, not cache strategy.
Which lightweight data format is commonly preferred in REST APIs for quick parsing and transmission of objects, such as returning user settings?
Explanation: JSON is lightweight, easy to parse, and widely used for transmitting object data in REST APIs, enabling fast serialization and deserialization. HTML is intended for web page markup, not data transport. CSV works well for tabular data but not for complex nested objects. XSLT is used for transforming XML, not as a transport format.
When a REST API returns a large list of results, such as product inventory records, what method is typically used to improve performance and user experience?
Explanation: Pagination splits large result sets into smaller pages, allowing clients to fetch only what they need and reducing server workload. Fragmentation involves breaking data or files, which is not a standard API practice. Inline scripting is unrelated to data retrieval. Reverse proxying helps route requests but does not address handling large datasets.
Which approach helps decrease REST API latency by placing data closer to users, for instance, when serving global users with a static set of images?
Explanation: A Content Delivery Network distributes resources to multiple locations worldwide, reducing latency by serving data from the nearest point to users. Client-side validation improves user input but does not impact latency. Regular expression filtering processes data but does not affect server proximity. API key rotation relates to security, not performance.
If a client frequently requests data that does not change between calls, such as a static country list, what optimization should be implemented to prevent repeated processing?
Explanation: Client-side caching stores previously fetched data, avoiding repeated network requests and unnecessary server load for static resources. Deep linking refers to navigation directly to specific contents, not caching. Increasing rate limits allows more requests, which does not minimize redundant calls. Switching to synchronous calls would actually slow down response handling.
Why is returning concise and standardized error messages, such as HTTP 400 with a short description, important for REST API performance?
Explanation: Concise error messages reduce the amount of data transmitted, leading to faster responses and improved performance. Ensuring redirects is a different role; concise messages don't manage that. Increasing response time is actually negative; concise messages do the opposite by speeding it up. Allowing unlimited payload sizes is not related and can diminish performance.
Which option can reduce CPU load on REST API servers when dealing with expensive operations, such as generating analytics reports on demand?
Explanation: Request throttling limits the number of requests processed in a given time, preventing server overload from heavy operations. Response encryption focuses on securing data, not managing server load. Random user-agent headers are not related to server computation. Monolithic architecture refers to software design and does not inherently reduce CPU load.
What technique can be used to reduce the size of API responses for faster transfer, for example, compressing JSON payloads sent to clients?
Explanation: GZIP compression reduces the size of the response sent over the network, improving transmission speed. Socket communication changes the protocol and is not specific to compression. Inline CSS relates to web page styling, not API payloads. Port forwarding remaps network ports but does not affect the size of response data.