backend-infrastructure

name	backend-infrastructure
description	Build scalable backend systems with Node.js, Python, databases, APIs, authentication, and cloud deployment. Use when developing server-side applications, APIs, or infrastructure systems.

Backend & Infrastructure Skill

Build production-grade backend systems and APIs.

Quick Start

Create a simple REST API with Express.js:

import express from 'express';
import cors from 'cors';

const app = express();
app.use(cors());
app.use(express.json());

// In-memory database for demo
let users = [];

// GET all users
app.get('/api/users', (req, res) => {
  res.json(users);
});

// POST new user
app.post('/api/users', (req, res) => {
  const user = { id: Date.now(), ...req.body };
  users.push(user);
  res.status(201).json(user);
});

// GET user by ID
app.get('/api/users/:id', (req, res) => {
  const user = users.find(u => u.id === parseInt(req.params.id));
  if (!user) return res.status(404).json({ error: 'Not found' });
  res.json(user);
});

app.listen(3000, () => console.log('Server running on port 3000'));

Backend Stack Overview

Web Frameworks

• Express.js (Node.js): Fast, flexible, minimal
• FastAPI (Python): Modern, async, auto-docs
• Spring Boot (Java): Enterprise-grade, feature-rich
• Django (Python): Full-featured with ORM

Database Technologies

• PostgreSQL: Powerful relational database
• MongoDB: Document-based NoSQL
• Redis: In-memory data store for caching
• Elasticsearch: Search and analytics engine

API Design

• REST: Industry standard API design
• GraphQL: Query language for APIs
• gRPC: High-performance RPC framework

Authentication & Security

• JWT: Stateless authentication
• OAuth 2.0: Delegated authorization
• bcrypt: Password hashing
• CORS: Cross-origin resource sharing

Cloud & Deployment

• Docker: Container technology
• Kubernetes: Container orchestration
• AWS: Cloud platform (EC2, RDS, Lambda)
• CI/CD: GitHub Actions, GitLab CI

API Best Practices

Proper HTTP Methods

// RESTful API endpoints
GET    /api/users           // List all users
GET    /api/users/:id       // Get user by ID
POST   /api/users           // Create user
PUT    /api/users/:id       // Update user
DELETE /api/users/:id       // Delete user
PATCH  /api/users/:id       // Partial update

Error Handling

// Structured error responses
{
  "error": "Bad Request",
  "code": 400,
  "message": "Email is required",
  "timestamp": "2025-11-18T22:30:00Z"
}

Database Connection

# Using SQLAlchemy with FastAPI
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

DATABASE_URL = "postgresql://user:password@localhost/dbname"
engine = create_engine(DATABASE_URL)
SessionLocal = sessionmaker(bind=engine)

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

Scaling Strategies

1. Horizontal Scaling: Add more server instances
2. Caching Layer: Redis for frequent queries
3. Database Optimization: Indexing, query optimization
4. Load Balancing: Distribute traffic across servers
5. Asynchronous Processing: Background jobs, message queues

Security Essentials

✅ Use HTTPS for all communications ✅ Validate all user inputs ✅ Use parameterized queries to prevent SQL injection ✅ Implement rate limiting ✅ Hash passwords with bcrypt ✅ Use environment variables for secrets ✅ Implement proper logging and monitoring

Learning Resources

• Express.js Documentation
• FastAPI Documentation
• PostgreSQL Documentation
• RESTful API Design Best Practices
• Backend Masters Course

Practice Projects

1. Beginner: Blog API with CRUD operations
2. Intermediate: Social media backend with authentication
3. Advanced: E-commerce platform with payment integration

Monitoring & Observability

• Logging: Winston, Morgan, Pino
• Monitoring: Prometheus, Grafana
• Tracing: Jaeger, Zipkin
• APM: DataDog, New Relic