Stack playbook · Snapshot 23 October 2026
Astro on Amazon CloudFront: readiness playbook
What 109 measured sites on this stack get right, where they fall short, and the Astro on Amazon CloudFront-specific steps that close each gap.
- Sites measured
- 109
- Median readiness index
- 72/100
- Profiles on this stack
- 19
detected from homepage HTML and headers
all sites: 64
top-50K sites
Readiness by lane
Enable
86/100
All sites 77
Harden
61/100
All sites 55
Accelerate
78/100
All sites 63
Recover
8/100
All sites 11
The Astro on Amazon CloudFront playbook
Gaps ordered by impact, with the platform-specific step where one exists.
security.txt published
13% observed · all sites 5.5%
Publish /.well-known/security.txt with at least Contact and Expires fields, as RFC 9116 requires, and review it before it expires.
HSTS kept for at least a year
51% observed · all sites 31%
Send Strict-Transport-Security on HTTPS responses. Start with a short max-age (for example 300 seconds), confirm every subdomain works over HTTPS, then raise it in steps to 31536000. Add includeSubDomains only when all subdomains are HTTPS. HSTS preload is optional and hard to undo; hstspreload.org itself does not recommend it by default.
On Amazon CloudFront: Attach a response headers policy with Strict-Transport-Security to each distribution.
CAA records limit who can issue certificates
16% observed · all sites 11%
Publish CAA records naming every CA you actually use, including the CAs your CDN uses for managed certificates. Add an iodef contact if you want reports.
DMARC policy enforces quarantine or reject
50% observed · all sites 31%
Publish DMARC with p=none and a reporting address first, fix any legitimate senders that fail SPF or DKIM alignment, then move to quarantine and finally reject.
Certificate lifetime of 100 days or less
8.3% observed · all sites 75%
Move to automated issuance and renewal now, while you still have time to test it.
DNSSEC signed
10% observed · all sites 8.1%
Enable DNSSEC at your DNS provider, then add the DS record at your registrar. Plan provider moves carefully: a stale DS record can make the domain fail to resolve.
Guide: Website Uptime Readiness: Prepare Before Traffic Arrives
Static files cached for 30 days or more
62% observed · all sites 50%
Give versioned (fingerprinted) CSS, JavaScript, fonts and images Cache-Control: public, max-age=31536000, immutable, and change the file name whenever the content changes.
Content Security Policy present
43% observed · all sites 31%
Start with Content-Security-Policy-Report-Only to see what would break, tighten the policy over a few weeks, then enforce it.
Guide: Payment Security and PCI DSS: What Website Owners Need to Know
Where Astro on Amazon CloudFront sites lead
- Modern image formats in use83% observedall sites 40%
- No render-blocking scripts in <head>77% observedall sites 44%
- Offscreen images lazy-loaded93% observedall sites 61%
- Referrer-Policy set46% observedall sites 23%