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https://www.twosigma.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
90
GRADE
A
FIX
0
REVIEW
3
PASS
6
INFO
0
Probed from Madrid, Spain
200 OK
Checks
9
6 PASS 3 REVIEW
B
DNS Records
2 A records, 29 ms lookup
REVIEW
2 A records, 29 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 141.193.213.10, 141.193.213.11
Info::
No IPv6 (AAAA) records
Warning::
CNAME record at zone apex
A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.
Got: wp.wpenginepowered.com
Info::
No NS records found
Info::
No MX records — email not configured via DNS
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 29 ms
Got: 29 ms
A141.193.213.10, 141.193.213.11
AAAA—
CNAMEwp.wpenginepowered.com
NS—
MX—
TXT—
CAALookup not available with standard resolver
Resolved in 29 ms

A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.

Why this matters

CNAME at the apex (example.com) breaks every other apex record (MX, TXT, NS) — DNS-protocol violation per RFC 1034.

Learn more ▾

RFC 1034 forbids CNAME alongside other records at the same name. Some DNS providers offer ALIAS / ANAME / flattened-CNAME records that work around this — use those instead. Otherwise apex-level CNAME breaks email (no MX), domain ownership verification (no TXT), and more.

Source: RFC 1034

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.

Why this matters

Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.

Learn more ▾

SPF complements DMARC. Both should be published. SPF records list authorized sending IPs (e.g., `v=spf1 include:_spf.google.com ~all` for Google Workspace). After publishing, verify in Google Postmaster Tools or mxtoolbox.

Source: RFC 7208 (SPF)

C
IPv6 Readiness
Action
No IPv6 support
REVIEW
No IPv6 support
Info::
No IPv6 (AAAA) records found
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No IPv6 Support
About 40% of internet users have IPv6. Consider adding AAAA records.

IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.

Why this matters

No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.

Source: Google IPv6 stats

B
TLS Certificate Expiry & Recommendations
238 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

238
days left
0d 30d 60d 90d+

Recommended actions

  • Extend HSTS max-age to at least 31536000 (1 year) to meet the preload list criteria
  • Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
  • Enable DNSSEC on your domain for DNS spoofing protection
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://www.twosigma.com

https://www.twosigma.com

37 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.twosigma.com20037 msHTTP/1.1cloudflare
A+
Crawlability
robots.txt present, sitemap with 21 URLs
PASS
robots.txt present, sitemap with 21 URLs
Info::
robots.txt is present
Got: 190 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 21 entries
Info::
Sitemap index with 21 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 190 B Sitemaps referenced 1 User-agents * Blocking No — crawling allowed
Crawl-delay: 10
# START YOAST BLOCK
# ---------------------------
User-agent: *
Disallow:

Sitemap: https://www.twosigma.com/sitemap_index.xml
# ---------------------------
# END YOAST BLOCK
sitemap.xml 200 OK
Type Sitemap Index URLs 21 entries Valid XML Yes
Child Sitemaps:
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
www/non-www redirect configured correctly (preferred: www)
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

200https://www.twosigma.com/
301https://twosigma.com/

Preferred variant: www

HTTP → HTTPS

301http://www.twosigma.com/ → https://www.twosigma.com/

Consistent

A+
Domain Intelligence
twosigma.com — via Gandi SAS, 25 years, 5 months old, hosted on Cloudflare
PASS
twosigma.com — via Gandi SAS, 25 years, 5 months old, hosted on Cloudflare
Info::
Domain registered until Mar 9, 2027 (11 months remaining)
Info::
DNSSEC is not enabled
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Info::
Registrar: Gandi SAS
Info::
Hosting: Cloudflare
Got: AS209242
Domain expiry

267 days

March 9, 2027

SSL certificate

238 days

Issued by DigiCert Inc

Domain age

25 years, 5 months

Registered March 9, 2001

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Cloudflare

ASN AS209242

141.193.213.10

Registrar

Gandi SAS

Lock status unknown 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable DNSSEC to protect visitors from DNS spoofing
Registrar Gandi SAS
Created March 9, 2001 (25 years, 5 months ago)
Expires March 9, 2027 (11 months)
Last Updated November 12, 2025
Name Servers ns1.twosigma.com, ns2.twosigma.com, ns4.twosigma.com, ns5.twosigma.com
DNSSEC Not enabled
Hosting
IP Address 141.193.213.10
ASN AS209242 (CLOUDFLARESPECTRUM Cloudflare, Inc., US)
Provider Cloudflare
Data source: rdap (0.1s)

DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.

Why this matters

Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.

Learn more ▾

DNSSEC adds cryptographic signatures to DNS records, preventing forged responses from poisoning resolver caches. Without it, an attacker who controls the network path can redirect your domain to a malicious server before any HTTPS handshake happens. Most modern registrars (Cloudflare, Google Domains, Route 53) enable it with one toggle.

Source: ICANN / RFC 4033

A+
HTTP Probe Timing
Total 266 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
137 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
1 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
26 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
263 ms
Total Time Total request time from DNS lookup through full response.
266 ms

Connection waterfall

DNS Lookup 137 ms TCP Connect 1 ms TLS Handshake 26 ms Server Processing 100 ms Content Transfer 3 ms
A+
CDN & Delivery
Cloudflare (HIT)
PASS
Cloudflare (HIT)
Info::
Site is served via Cloudflare CDN (edge: MAD)
Got: cf-ray: 9e8bdc93cb3e6dc0-MAD
Info::
CDN cache status: HIT
CDN Detected: Cloudflare
Provider Cloudflare Cache Status HIT Evidence cf-ray: 9e8bdc93cb3e6dc0-MAD
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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