REST (Representational State Transfer) is an architectural style for providing standards between computer systems on the web, making it easier for systems to communicate with each other. RESTful systems are stateless and separate the concerns of client and server.

What is idempotency in the context of APIs?

An idempotent HTTP method is an HTTP method that can be called many times without different outcomes. It would not be considered idempotent if it results in a different outcome on subsequent calls. For example, a GET request is idempotent, but a POST request is not.

System Design Interview

API Design

Design clean, intuitive, and scalable APIs. Understand the nuances of REST, GraphQL, and how to handle versioning, authentication, and rate limiting.

Example: RESTful API Endpoint in Python with Flask

A simple Flask application demonstrating a RESTful API endpoint to get a user by their ID.


                                from flask import Flask, jsonify
                                
                                app = Flask(__name__)
                                
                                users = {
                                    1: {'username': 'alex', 'email': 'alex@example.com'},
                                    2: {'username': 'jane', 'email': 'jane@example.com'}
                                }
                                
                                @app.route('/users/<int:user_id>', methods=['GET'])
                                def get_user(user_id):
                                    user = users.get(user_id)
                                    if user:
                                        return jsonify(user)
                                    return jsonify({'error': 'User not found'}), 404

Our AI Coach can help you design a full-fledged REST API, discuss the pros and cons of GraphQL, and explore advanced topics like API security and authentication mechanisms.