REST Design Principles
Resource-Oriented Design
Everything is a resource — an object with data and relationships.
Products ──contains──> Product ──has──> Review
│
+──has──> Category
Key Principles
| Principle | Description | Example |
|---|---|---|
| Identify resources | Use nouns, not verbs | /products not /getProducts |
| Use HTTP methods | GET=read, POST=create, PUT=update, DELETE=remove | GET /products/1 |
| Representations | Resources have multiple representations | JSON, XML |
| Stateless | No server-side session | JWT token per request |
| Uniform interface | Consistent URL patterns | /resource/{id} |
Good vs Bad API Design
# Bad (verb-oriented)
GET /getUser?id=123
POST /createProduct
POST /deleteProduct?id=456
# Good (resource-oriented)
GET /users/123
POST /products
DELETE /products/456
Naming Conventions
| Pattern | Example | Correct |
|---|---|---|
| Plural nouns | /products |
Yes |
| Singular nouns | /product |
No |
| Hyphenated | /order-items |
Yes |
| camelCase | /orderItems |
No |
| Nested resources | /users/123/orders |
Yes |
REST Best Practices
Principles
- Stateless communication
- Client-server separation
- Cacheable responses
- Uniform interface
HTTP Methods
- GET: Read (idempotent, safe)
- POST: Create
- PUT: Full update (idempotent)
- PATCH: Partial update
- DELETE: Remove (idempotent)
Status Codes
- 2xx: Success
- 3xx: Redirection
- 4xx: Client error
- 5xx: Server error
Key Points
- Understanding REST Design Principles is essential for production systems
- Always consider scalability and maintainability
- Test thoroughly before deploying to production
- Monitor performance and set up alerting
Common Patterns
- Validation: Always validate input at the boundary
- Error Handling: Use structured error responses
- Logging: Log key events for debugging
- Testing: Unit, integration, and load tests
- Documentation: Keep docs updated with code changes
Practice Problems
Design and implement a solution for REST Design Principles in a backend system. Consider scalability, error handling, and production readiness.
Solution
// REST Design Principles implementation
// Key aspects: validation, error handling, logging, testing
public class RESTDesignPrinciples {
// Production-ready implementation
}Identify and handle edge cases for REST Design Principles. What happens under high load, with invalid input, or during failures?
Solution
// Edge case handling:
// 1. Null/empty input -> validation
// 2. High load -> rate limiting, queuing
// 3. Failures -> retries, circuit breaker
// 4. Concurrent access -> locks, idempotencyWrite a testing strategy for REST Design Principles. Include unit tests, integration tests, and performance tests.
Solution
// Test plan:
// - Unit: 80% coverage target
// - Integration: API contracts
// - Performance: latency, throughput
// - Chaos: failure injectionQuiz
1. In REST, resources should be identified using:
2. Which is a correctly designed REST URL?
3. What is the primary purpose of REST Design Principles?
4. What is a common mistake when implementing REST Design Principles?
Flashcards
Question
REST resource design rule
Click to reveal answer
Answer
Use nouns, not verbs. HTTP methods are the verbs.
Question
Should REST URLs be plural or singular?
Click to reveal answer
Answer
Always plural: /products, /users, /orders
Question
What is REST Design Principles?
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Answer
REST Design Principles is a key concept in backend development.
Question
When to use REST Design Principles?
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Answer
Use REST Design Principles when building production systems that require reliability, scalability, and maintainability.
Question
REST Design Principles best practices
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Answer
Follow SOLID principles, write clean code, test thoroughly, document decisions, and monitor in production.
Revision Notes
Key Takeaways
- 1.Everything is a resource — use nouns, not verbs
- 2.HTTP methods define actions on resources
- 3.Use plural nouns and consistent naming conventions
- 4.Nested resources show relationships
Interview Tips
- •Explain why /products is better than /getProducts
- •Know plural vs singular noun conventions
Cheat Sheet
REST Design
- Resources: Nouns, plural (
/products) - Actions: HTTP methods (GET, POST, PUT, DELETE)
- Naming: Hyphenated, lowercase (
/order-items) - Nesting:
/users/123/ordersfor relationships