Oct 08, 2026 by Offer

REST API design: Answer Guide 2027

Good REST API design means resource-based URLs, correct HTTP verbs, and predictable status codes: GET /orders/123 retrieves, POST /orders creates, PUT or PATCH updates, DELETE removes. In a rest api interview, lead with these conventions, then cover statelessness, versioning, and pagination — the four topics interviewers almost always probe.

What This Tests in a Rest api interview Question

Whether you know REST conventions cold: nouns not verbs in URLs, proper HTTP methods and status codes.
Whether you understand statelessness: each request carries everything the server needs.
Whether you think about real-world concerns: versioning, pagination, authentication, and error formats.

How to Answer a Rest api interview Question

Lay out the conventions: resource nouns, GET/POST/PUT/PATCH/DELETE semantics, and status codes like 200, 201, 400, 404.
Explain statelessness and why it matters for scalability: no session state on the server.
Cover the practical layer: version in the URL or header, paginate list endpoints, return consistent error payloads.

Example phrasing: "I design around resources: GET /orders/123, POST /orders, PATCH /orders/123, with 201 on creation and 404 on missing resources. Endpoints are stateless, versioned, and paginated, and errors return a consistent JSON shape with a code and message."

Common Mistakes in a Rest api interview Question

Putting verbs in URLs like /getOrders — the HTTP method already says the verb.
Returning 200 for everything including errors, which breaks client handling.
Forgetting pagination on list endpoints, a classic scalability miss.

API design questions are where backend interviews separate candidates who have shipped services from those who have only read about them. Nail resources, verbs, status codes, and pagination in two minutes and the system-design portion gets much easier.

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FAQ

What makes a good REST API in a rest api interview?

Resource-based URLs, correct HTTP verbs, meaningful status codes, statelessness, versioning, and pagination.

What is statelessness in REST?

Each request contains all information the server needs; the server stores no client session between requests.

PUT vs PATCH?

PUT replaces the whole resource; PATCH applies a partial update — both are idempotent in well-designed APIs.

How should APIs handle errors?

With appropriate status codes (4xx for client errors, 5xx for server errors) and a consistent error response body.

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