Web API Interview Questions and Answers

Ques 1. What is JSON Web Token (JWT) and how is it used in Web APIs?

JWT is a compact, URL-safe means of representing claims to be transferred between two parties. In Web APIs, it is often used for authentication and information exchange.

Example:

Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

Ques 2. What is the role of OAuth in Web API security?

OAuth is an open standard for access delegation commonly used in the context of user authentication and authorization. It allows third-party applications to access resources on behalf of a user without exposing their credentials.

Ques 3. What is HATEOAS, and how does it relate to RESTful Web APIs?

HATEOAS (Hypermedia As The Engine Of Application State) is a constraint in the REST architectural style where the response from a server provides links to related resources. It allows clients to navigate a web application dynamically.

Ques 4. Explain the concept of Hypermedia in the context of RESTful Web APIs.

Hypermedia refers to the inclusion of hyperlinks in a response, allowing clients to discover and navigate related resources. It is a key aspect of HATEOAS and enhances the flexibility and discoverability of RESTful APIs.

Ques 5. What are the advantages and disadvantages of using JSON Web Tokens (JWT) for authentication in Web APIs?

Advantages include statelessness, compactness, and ease of implementation. Disadvantages may include potential security risks if not properly implemented, and the inability to revoke tokens before expiration.