REST API best practices in HLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

HTTP Methods Usage in REST APIs

Which HTTP method is the most appropriate to update a resource partially in a REST API?

A GET

B PATCH

C PUT

D DELETE

💡 Hint

Think about the method that allows partial updates without replacing the entire resource.

PATCH is used for partial updates to a resource, while PUT replaces the entire resource.

❓ Architecture

intermediate

Statelessness in REST APIs

What is the main advantage of designing a REST API to be stateless?

A It enables the server to handle each request independently without client context.

B It allows the server to store client session data for faster responses.

C It requires the client to maintain a persistent connection to the server.

D It forces the server to keep track of user authentication state.

💡 Hint

Consider how statelessness affects scalability and server load.

Statelessness means each request contains all information needed, allowing servers to handle requests independently and scale easily.

❓ scaling

advanced

Handling High Traffic in REST APIs

Which strategy best helps a REST API handle sudden spikes in traffic without degrading performance?

A Use synchronous processing for all requests to maintain order.

B Store all client sessions on the server to reduce repeated authentication.

C Implement rate limiting and caching mechanisms.

D Disable load balancers to reduce network overhead.

💡 Hint

Think about controlling request volume and reducing repeated work.

Rate limiting prevents overload by limiting requests per client, and caching reduces repeated processing, improving performance during spikes.

❓ tradeoff

advanced

Choosing Between JSON and XML for REST APIs

What is a key tradeoff when choosing JSON over XML as the data format for a REST API?

A XML supports namespaces and schema validation, JSON does not.

B JSON is more verbose but easier to parse than XML.

C JSON requires more bandwidth due to its structure.

D XML is less human-readable compared to JSON.

💡 Hint

Consider features related to data validation and complexity.

XML supports namespaces and schema validation, which JSON lacks, but JSON is simpler and lighter for most REST APIs.

❓ estimation

expert

Estimating API Server Capacity

You expect 10,000 requests per minute to your REST API. Each request takes 100ms of server processing time. How many concurrent server threads are needed to handle the load without queuing?

A Approximately 10 threads

B Approximately 100 threads

C Approximately 1,000 threads

D Approximately 17 threads

💡 Hint

Calculate how many requests happen per second and how many can be processed simultaneously.

10,000 requests/min = ~167 requests/sec. Each takes 0.1s, so concurrent threads = 167 * 0.1 = ~17.