Secure Coding Standards and Guidelines

Establishing and enforcing secure coding standards prevents XSS vulnerabilities from being introduced during development. These standards should be specific to your technology stack while addressing common XSS patterns. Document approved methods for handling user input, required encoding functions for different contexts, and forbidden practices like using innerHTML with user data. Make these guidelines easily accessible and include code examples showing both secure and insecure patterns.

Implement secure defaults that make the safe choice the easy choice. Create wrapper functions or components that handle encoding automatically, so developers don't need to remember security details for common operations. For example, a secure component for displaying user comments that handles all necessary sanitization internally. When developers can use <SafeComment content={userInput} /> instead of manually encoding, they're more likely to do the right thing.

Code templates and snippets should embody security best practices. IDE snippets for common patterns should include proper encoding. Project templates should have CSP headers configured, security middleware enabled, and example code demonstrating secure patterns. When developers start from secure foundations, they're less likely to introduce vulnerabilities. Regular security training ensures developers understand not just what the standards are, but why they exist and how attackers exploit violations.