Common REST API Interview Questions

Introduction

• Presenter: Kevin Way, Product Manager
• Objective: To help prepare for REST API interview questions

Importance of REST APIs

• Prominent in web services
• Critical for software engineering interviews

Question 1: How are REST APIs Stateless?

• Stateful: Server stores client data (e.g., usernames, passwords)
• Stateless: Each client request must contain all necessary data
• REST requires client state not to be stored on the server

Question 2: Explain the HTTP Methods

• GET: Fetch a resource
• POST: Create a resource
• PUT: Update a resource
• DELETE: Delete a resource
• Correspond to CRUD operations (Create, Read, Update, Delete)

Question 3: Explain the HTTP Status Codes

• 200 codes: Successful requests
• 400 codes: Client-side errors
• 500 codes: Server-side errors

Question 4: What is a URI?

• URI: Uniform Resource Identifier
• Types:
  • URN: Unique, persistent (e.g., ISBN)
  • URL: Web address, common in REST APIs

Question 5: Best Practices for Designing URIs

• Standardize URIs
• Use forward slashes for hierarchy
• Use plural nouns for branches
• Use hyphens for multiple words
• Use lowercase
• Avoid file extensions

Question 6: Differences Between REST and SOAP

• REST: Architecture for web services
• SOAP: Protocol for exchanging structured data
• REST: Flexible standards, supports JSON, XML
• SOAP: Strict standards, only supports XML
• SOAP is more niche, used for regulated data

Question 7: Differences Between REST and AJAX

• REST API: Handles HTTP requests, architecture
• AJAX: Collection of web technologies for asynchronous requests
• AJAX can be used to send RESTful requests
• REST API cannot be replaced by AJAX

Question 8: Tools for Developing and Testing REST APIs

• Language-dependent (e.g., Java, Node.js, Python)
• Framework Example: Express for Node.js
• Testing Tools: Postman for ensuring resource delivery

Question 9: Real-world Examples of REST APIs

• Example: GET requests for HTML from a server
• Used for database manipulation, file data retrieval, and hosting websites

Advantages and Disadvantages of REST APIs

• Advantages:

  • Easy to learn
  • Supports multiple data formats (JSON, XML)
  • Statelessness simplifies client experience
  • Scalability due to client-server independence

• Disadvantages:

  • Cannot maintain sessions due to statelessness
  • Lacks built-in security
  • Requires versioning for backward compatibility
  • URI consistency can be difficult for complex projects

Conclusion

• Refresh on REST APIs
• Common interview questions reviewed
• Resources for further preparation: tryexponent.com