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REST URI Design Interview Questions and Answers

Master REST URI Design with the top 15 interview questions and answers. Learn URI vs URL, resource naming conventions, nested resources, query parameters, pagination, filtering, versioning, Spring Boot examples, production best practices, and common interview questions.

Introduction

A well-designed URI (Uniform Resource Identifier) is the foundation of every REST API. Clean, consistent, and meaningful URIs make APIs easy to understand, maintain, and integrate with. Poor URI design leads to confusing APIs, inconsistent implementations, and poor developer experience.

Interviewers frequently ask questions about URI naming conventions, URI vs URL, nested resources, query parameters, pagination, filtering, versioning, and REST resource design.

In this guide, you'll learn the 15 most important REST URI Design interview questions with production-ready explanations, Spring Boot examples, architecture diagrams, best practices, common mistakes, and interview follow-up questions.

What You'll Learn

After completing this guide, you'll be able to:

  • Design clean REST URIs.
  • Understand URI vs URL vs URN.
  • Follow industry naming conventions.
  • Design nested resources.
  • Implement pagination and filtering.
  • Version REST APIs correctly.
  • Answer REST API design interview questions confidently.

REST URI Design Overview

                 REST URI Design

                     Client
                        │
                HTTP Request
                        │
        GET /employees/101/orders
                        │
                        ▼
                Spring Boot API
                        │
                        ▼
                  Database
                        │
                        ▼
                 JSON Response

1. What is a URI?

Short Answer

A URI (Uniform Resource Identifier) uniquely identifies a resource in a REST API.

Example

/employees

/products

/orders/101

/customers/500

Each URI represents a resource rather than an action.

Production Example

GET /customers/1001

Returns customer information.

Interview Follow-up

Can two different resources have the same URI?

Answer: No.

2. What is the Difference Between URI and URL?

Short Answer

A URL is a type of URI that specifies both the resource and how to access it.

URI URL
Identifies Resource Identifies + Locates Resource
Broader Concept Subset of URI
May not include protocol Includes protocol

Example

URI

/employees/100

URL

https://api.company.com/employees/100

Common Mistakes

Using URI and URL interchangeably in interviews.

3. What are REST URI Naming Conventions?

Best Practices

  • Use nouns.
  • Use lowercase letters.
  • Use hyphens.
  • Avoid spaces.
  • Keep URIs readable.
  • Avoid file extensions.

Good

/employees

/customer-orders

/payment-history

Bad

/GetEmployee

/createCustomer

/deleteOrder

Interview Tip

Always design URIs as resources.

4. Why Should REST URIs Use Nouns Instead of Verbs?

Short Answer

HTTP methods already define the action.

The URI should represent the resource.

Correct

GET /employees

POST /employees

Incorrect

GET /getEmployees

POST /createEmployee

Production Example

GitHub API

GET /users

Stripe API

POST /payments

5. Should Resources be Singular or Plural?

Best Practice

Use plural resource names.

Good

/employees

/orders

/customers

Bad

/employee

/order

/customer

Why?

Collections naturally use plural names.

6. What are Nested Resources?

Short Answer

Nested resources represent relationships between resources.

Example

/customers/100/orders

/orders/200/items

/employees/50/projects

Internal Structure

Customer

│

├── Orders

│     ├── Order 1

│     ├── Order 2

│

└── Addresses

Production Example

Amazon

GET /customers/500/orders

7. How Should Query Parameters be Used?

Purpose

Query parameters filter or modify results.

Examples

Filtering

GET /employees?department=IT

Sorting

GET /employees?sort=name

Searching

GET /employees?name=John

Common Mistakes

Using query parameters for resource identification.

Incorrect

/employee?id=10

Better

/employees/10

8. How is Pagination Implemented?

Production Example

GET /employees?page=1&size=20

Response

20 Employees

Spring Boot Example

@GetMapping
public Page<Employee> employees(
        Pageable pageable){

    return repository.findAll(pageable);

}

Benefits

  • Better performance
  • Smaller payloads
  • Faster responses

9. How are Filtering and Sorting Implemented?

Filtering

GET /products?category=Laptop

Sorting

GET /products?sort=price

Multiple Filters

GET /products?category=Laptop&brand=Apple

Production Example

E-commerce websites.

10. How Should API Versioning be Designed?

URI Versioning

/v1/customers

/v2/customers

Header Versioning

Accept:
application/vnd.company.v2+json

Best Practice

URI versioning is the simplest and most commonly used.

11. What Characters Should be Used in URIs?

  • Lowercase
  • Hyphen (-)
  • Numbers
  • Forward Slash

Good

/employee-address

/order-history

Bad

/EmployeeAddress

/order_history

/Employee Address

12. What are Common URI Design Mistakes?

  • Using verbs.
  • Mixing singular and plural names.
  • Uppercase letters.
  • Exposing database table names.
  • Long URIs.
  • Deep nesting.
  • Using spaces.
  • Including implementation details.

Example

Bad

/employeeTable/getEmployeeById

Good

/employees/101

13. How are URIs Designed in Enterprise Applications?

Example Banking API

GET     /accounts

GET     /accounts/100

POST    /accounts

PUT     /accounts/100

DELETE  /accounts/100

Architecture

Client

↓

API Gateway

↓

Spring Boot

↓

Business Service

↓

Database

14. Design a REST URI for an Online Shopping Application

Resources

/products

/categories

/orders

/payments

/cart

/users

Nested Resources

/users/101/orders

/orders/500/items

/products/100/reviews

Filtering

/products?brand=Apple

/products?price=1000

/products?category=Laptop

Pagination

/products?page=2&size=25

15. What are REST URI Design Best Practices?

  • Use nouns instead of verbs.
  • Use plural resource names.
  • Keep URIs simple.
  • Use lowercase letters.
  • Use hyphens instead of underscores.
  • Use HTTP methods for actions.
  • Use query parameters for filtering.
  • Support pagination.
  • Keep URI hierarchy meaningful.
  • Version APIs consistently.

URI Design Summary

Design Principle Recommendation
Resource Naming Nouns
Resource Collection Plural
Case Lowercase
Word Separator Hyphen (-)
Filtering Query Parameters
Pagination page & size
Sorting sort Parameter
Versioning /v1/, /v2/
Resource Identification Path Variables
Actions HTTP Methods

Interview Tips

When answering URI Design questions:

  1. Explain that URIs identify resources.
  2. Differentiate URI and URL.
  3. Use nouns instead of verbs.
  4. Prefer plural resource names.
  5. Explain nested resources.
  6. Demonstrate filtering and pagination.
  7. Discuss API versioning strategies.
  8. Mention Spring Boot path variables and query parameters.
  9. Avoid exposing implementation details.
  10. Use real-world API examples.

Key Takeaways

  • URIs uniquely identify REST resources.
  • REST URIs should represent resources, not actions.
  • Use nouns, plural names, lowercase letters, and hyphens.
  • Path variables identify resources, while query parameters filter and sort data.
  • Nested resources represent relationships between entities.
  • Pagination improves performance for large datasets.
  • API versioning ensures backward compatibility.
  • Clean URI design improves readability, maintainability, and developer experience.
  • Well-designed URIs are a hallmark of production-ready REST APIs.
  • URI design is one of the most frequently tested topics in REST API interviews.