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https://www.janestreet.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
88
GRADE
B
FIX
1
REVIEW
3
PASS
5
INFO
0
Probed from Madrid, Spain
200 OK
Checks
9
5 PASS 3 REVIEW 1 FIX
D
CDN & Delivery
Action
No CDN detected
FIX
No CDN detected
Warning::
No CDN detected
A CDN can significantly improve load times for users around the world by caching content at edge nodes closer to them.
No CDN detected

Consider using a CDN to improve global delivery speed and reduce origin load.

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
Crawlability
robots.txt present, no sitemap
REVIEW
robots.txt present, no sitemap
Info::
robots.txt is present
Got: 1130 bytes
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

A sitemap helps search engines discover and index your pages more efficiently.

Why this matters

No sitemap.xml — Google relies on crawl-graph discovery alone, slowing indexing of deep or fresh URLs.

Learn more

A sitemap accelerates Google's discovery of new and updated content. Most CMSes auto-generate one; static-site frameworks need a build-step plugin. Reference it from robots.txt and submit in Search Console to confirm Google can fetch it.

Source: sitemaps.org / Google Search Central

Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Why this matters

robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.

Source: sitemaps.org

robots.txt 200 OK
Size 1130 B Sitemaps referenced 0 User-agents * Blocking No — crawling allowed
User-agent: *
Disallow: /static/
Disallow: /welcome-guide/
Disallow: /benefits/
Disallow: /welcome-guide/
Disallow: /institutional-services/resources-for-volatile-markets/
Disallow: /solutions/
Disallow: /bonus-problems/
Disallow: /excel-obstacle-course/
Disallow: /logo-meaning/
Disallow: /quantitative-researcher/
Disallow: /apply-quantitative-researcher/
Disallow: /join-jane-street/exploding-offers/
Disallow: /enigmatologist-description-nyc/
Disallow: /enigmatologist-puzzle-nyc/
Disallow: /apply-enigmatologist-nyc-b5d9kfs0i1/
Disallow: /enigmatologist-description-ldn/
Disallow: /enigmatologist-puzzle-ldn/
Disallow: /apply-enigmatologist-ldn-agyl3jwr7n/
Disallow: /what-we-do/global-capital-markets/
Disallow: /puzzle-tutorials/
Disallow: /party-puzzle/
Disallow: /see-hkg-email.html
Disallow: /see-ldn-email.html
Disallow: /join-jane-street/position/7304961002/
Disallow: /join-jane-street/apply/7304961002/
Disallow: /web-app/
Disallow: /solved/
Disallow: /curious/
Disallow: /join-jane-street/interviewing-deep-dive/
Disallow: /join-jane-street/ml-research-interviews
Disallow: /join-jane-street/ml-engineer-interviews

sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

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

Certificate validity

185
days left
0d 30d 60d 90d+

Recommended actions

  • Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
  • Submit your domain to hstspreload.org to be added to the Chrome preload list
  • 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
DNS Records
2 A records, 107 ms lookup
PASS
2 A records, 107 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 13.248.239.113, 166.117.199.99
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: janestreet.com
Info::
4 nameserver(s) configured
Got: ns-501.awsdns-62.com, ns-1215.awsdns-23.org, ns-613.awsdns-12.net, ns-1819.awsdns-35.co.uk
Info::
4 mail exchanger(s) configured
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
SPF record present in TXT
Info::
DNS resolution time: 107 ms
Got: 107 ms
A13.248.239.113, 166.117.199.99
AAAA
CNAMEjanestreet.com
NSns-501.awsdns-62.com, ns-1215.awsdns-23.org, ns-613.awsdns-12.net, ns-1819.awsdns-35.co.uk
MX
10 mxin1.mail.janestreet.com
10 mxin3.mail.janestreet.com
10 mxin4.mail.janestreet.com
10 mxin2.mail.janestreet.com
TXT
anthropic-domain-verification-1tvja2=TClVsR6hNQVZUIsw0Sc7y6xLv
security_contact=mailto:security-txt-ea6d70@janestreet.com
figma-domain-verification=776c503e3c6ceb675e7340a0819dd59a912de8e45105c6bc17ae68...
SPF v=spf1 +ip4:38.105.200.78 +ip4:38.105.200.79 +ip4:64.215.233.18 +ip4:64.215.233....
adobe-idp-site-verification=6fcf8cf7306c175e36f705c53a3891c98e9b0db928234c098684...
google-site-verification=A6LUH6cnfW5sYTr0INx_bV4lI2NWKJ6I9w4_0Epum7Y
adobe-sign-verification=e0c7f457a2c211021e8b7028ddf8a770
goodnotes-verification=45639188-7d16-417a-b272-dd714f748430
jamf-site-verification=T00q6fdYWgzHJcw3O6QK6g
smartsheet-site-validation=IGQuKGpF13IuzFsgbTvKb4BMYfxYVpFw
atlassian-domain-verification=r9oLqXP1JpiBGHoDxohmjvNyysRGPnPfz3Hda1mpYWgL/jc2tc...
_4tuir5rkiga8i5wvho3t2brhssiltnw
uber-domain-verification=dc610b3f-750e-4d16-82e7-a8cd5e042fe5
sterling-domain-verification=a4014a90cc2b4f7a8408e324283e96a6
slack-domain-verification=CS4d25GXHEkYncSMArj1YB7GmY6Tb1d0PvCH28o7
MS=ms95726908
cisco-ci-domain-verification=51449fb45ce25667ce39943677a9d5629fa108cf92cf4ee8bd6...
fxb7jqkw4y2k2dl22tfm6vdz1dxw2rs4
canva-site-verification=DOBZuEg-utLOzfmE2427DA
00D40000000Mzos=1TBPK00000000Pp
CAALookup not available with standard resolver
Resolved in 107 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.

A+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://www.janestreet.com

https://www.janestreet.com

414 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.janestreet.com200414 msHTTP/1.1nginx/1.14.1
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.janestreet.com/
301https://janestreet.com/

Preferred variant: www

HTTP → HTTPS

301http://www.janestreet.com/ https://www.janestreet.com:443/

Consistent

A+
Domain Intelligence
janestreet.com — via MarkMonitor Inc., 23 years, 6 months old, hosted on AWS
PASS
janestreet.com — via MarkMonitor Inc., 23 years, 6 months old, hosted on AWS
Info::
Domain registered until Jan 11, 2028 (1 years, 9 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: MarkMonitor Inc.
Info::
Hosting: AWS
Got: AS16509
Domain expiry

548 days

January 11, 2028

SSL certificate

185 days

Issued by Amazon

Domain age

23 years, 6 months

Registered January 11, 2003

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

166.117.199.99

Registrar

MarkMonitor Inc.

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 MarkMonitor Inc.
Created January 11, 2003 (23 years, 6 months ago)
Expires January 11, 2028 (1 years, 9 months)
Last Updated December 10, 2025
Name Servers ns-1215.awsdns-23.org, ns-1819.awsdns-35.co.uk, ns-501.awsdns-62.com, ns-613.awsdns-12.net
DNSSEC Not enabled
Hosting
IP Address 166.117.199.99
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.3s)

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 481 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
74 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.
302 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
481 ms
Total Time Total request time from DNS lookup through full response.
481 ms

Connection waterfall

DNS Lookup 74 ms TCP Connect 1 ms TLS Handshake 302 ms Server Processing 104 ms Content Transfer 1 ms
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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