Security & Best Practices

Building an app is one thing; keeping it secure is another. Express provides the foundation, but you must implement additional layers to protect your users.

1. Using Helmet

Helmet helps you secure your Express apps by setting various HTTP headers. It's a collection of 15 smaller middleware functions that set security-related HTTP headers.

const helmet = require('helmet');
app.use(helmet());

2. Rate Limiting

To prevent Brute Force or DDoS attacks, use express-rate-limit to limit repeated requests to public APIs and endpoints.

const rateLimit = require('express-rate-limit');

const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100 // limit each IP to 100 requests per windowMs
});

app.use('/api/', limiter);

3. SQL/NoSQL Injection

Always use parameterized queries or ODMs like Mongoose and Sequelize. Never pass unsanitized user input directly into a database query.

4. Production Environment

• Gzip Compression: Use the compression middleware.
• Don't run as root: Use a non-privileged user on your server.
• Environment Variables: Store secrets in .env, never in code.
• Logging: Use Winston or Pino for structured logging.

Final Checklist

1. Set NODE_ENV to production.
2. Use TLS/SSL (HTTPS).
3. Ensure dependencies are up to date (npm audit).
4. Implement strict CORS policies.