I am about to deploy my first major REST API and I'm nervous about security. I've implemented basic JWT authentication, but I'm worried about things like SQL injection, Rate Limiting, and Cross-Site Scripting (XSS). Beyond just checking tokens, what are the "must-have" security layers every professional backend should have in production?
3 answers
Security must be applied in layers. First, ensure you are using a library like helmet for Node.js to set secure HTTP headers. For SQL injection, never use string concatenation in queries; always use "Prepared Statements" or an ORM that handles parameterization automatically. Regarding JWTs, ensure they are stored in HttpOnly cookies to prevent XSS from stealing them. Most importantly, implement "Rate Limiting" using something like Redis to prevent brute-force attacks on your auth endpoints. Finally, always validate and sanitize every piece of incoming data using a schema validator.
Should we also look into CORS configurations even if our frontend and backend are on the same main domain?
Don't forget to hide your API versioning and detailed error messages in production. Giving away stack traces is like giving a map to hackers.
Great point, Sandra! Generic "Internal Server Error" messages are the way to go. Detailed logs should only ever exist on your secure logging server.
Definitely, Kenneth. Even on the same domain, a strict CORS (Cross-Origin Resource Sharing) policy is a vital defense. You should explicitly whitelist only your specific frontend origins and allowed methods (GET, POST, etc.). This prevents malicious third-party sites from making requests on behalf of your users. Also, consider implementing a "Web Application Firewall" (WAF) like Cloudflare. It can filter out known malicious IP addresses and common bot patterns before the traffic even reaches your server, saving your resources.