Security Headers: Add a Basic Response Hardening Layer

Security headers do not replace secure code, but they reduce common browser-side risks.

A public launch should include a sensible baseline.

What It Is

Security headers are HTTP response headers that instruct the browser how to handle framing, transport, MIME types, referrers, and related behavior.

Strict-Transport-Security: max-age=31536000
X-Content-Type-Options: nosniff
Referrer-Policy: strict-origin-when-cross-origin

Why It Matters

• They reduce avoidable exposure to common browser-level issues.
• They help enforce safer defaults across public traffic.
• They add trust and operational maturity to the deployment.

Best Practices

1. Ship a minimal baseline such as HSTS, X-Content-Type-Options, and Referrer-Policy.
2. Add X-Frame-Options or CSP framing rules where appropriate.
3. Test headers after CDN and proxy layers, not just locally.

Common Mistakes

• No security headers on production responses.
• Setting headers only on one route instead of the whole app.
• Breaking behavior with untested restrictive policies.

Quick Checklist

• Baseline headers present.
• Values tested on the public response.
• No regressions introduced by policy rules.

Final Takeaway

Security headers are part of disciplined delivery. They should not be an afterthought.