At a glance
- Workplace
- Hybrid
- Location
- Hybrid · Austin, TX
About Cloudflare
- At Cloudflare, we are on a mission to help build a better Internet. Today the company runs one of the world’s largest networks that powers millions of websites and other Internet properties for customers ranging from individual bloggers to SMBs to Fortune 500 companies. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code. Internet properties powered by Cloudflare all have web traffic routed through its intelligent global network, which gets smarter with every request. As a result, they see significant improvement in performance and a decrease in spam and other attacks. Cloudflare was named to Entrepreneur Magazine’s Top Company Cultures list and ranked among the World’s Most Innovative Companies by Fast Company.
- At Cloudflare, we’re not looking for people who wait for a polished roadmap; we’re looking for the builders who see the cracks in the Internet that everyone else has simply learned to live with. We value candidates who have the instinct to spot a "normalized" problem and the AI-native curiosity to create a solution using the latest tools. Our culture is built on iteration, leveraging AI to ship faster today to make it better tomorrow, while ensuring that every improvement, no matter how small, is shared across the team to lift everyone up. If you’re the type of person who values curiosity over bureaucracy, and that AI is a partner in solving tough problems to keep the Internet moving forward, you’ll fit right in.
- Cloudflare is building a new public Certificate Authority for the Internet. We are looking for a senior technical architect to help define the systems, protocols, and security architecture behind it.
- This role spans applied cryptography, Web PKI, distributed systems, security engineering, compliance, and Internet standards. It will help Cloudflare build a CA that operates safely at Internet scale while establishing a credible path from today's X.509 ecosystem toward post-quantum authentication using Merkle Tree Certificates (MTCs).
- Mission
- Define and guide the end-to-end architecture of Cloudflare's public Certificate Authority: a high-assurance, highly available system capable of issuing conventional publicly trusted certificates at Cloudflare scale while supporting Merkle Tree Certificates (MTCs) and the evolution toward a post-quantum Web PKI.
About the role
- The Senior Certificate Authority Architect will define the systems, protocols, and security architecture for Cloudflare's new public Certificate Authority. This role involves designing a high-assurance, scalable system that supports conventional X.509 certificates, Merkle Tree Certificates, and post-quantum authentication.
Responsibilities
- Define and maintain the end-to-end technical architecture of the public CA across issuance, key management, transparency, and revocation.
- Design root and intermediate CA trust hierarchies, HSM integration, key ceremonies, and key rotation strategies.
- Architect secure, resilient, and highly available issuance services for Internet-scale operations.
- Design certificate lifecycle systems including ACME, domain validation, CAA, and Certificate Transparency.
- Integrate MTC infrastructure and develop architectures for migration between X.509 and post-quantum authentication.
- Define threat models and security boundaries covering key compromise, unauthorized issuance, and supply-chain risks.
- Design systems for observability, independent verifiability, and reproducible builds.
- Develop failure containment and recovery mechanisms to ensure Internet availability during certificate replacement or incidents.
- Translate CA/Browser Forum requirements and root-program policies into technical and operational controls.
- Represent Cloudflare in industry standards work and collaborate with browser vendors, researchers, and auditors.
Requirements
- Substantial experience designing or operating security-critical systems.
- Deep expertise in at least one of: public Certificate Authorities, Web PKI, applied cryptography, TLS, Certificate Transparency, hardware-backed key management, or large-scale distributed security systems.
- Strong knowledge of certificate trust chains, issuance, validation, revocation, and key lifecycle management.
- Experience defining system trust boundaries, threat models, security invariants, and failure-handling strategies.
- Experience leading architecture across multiple engineering teams.
- Strong written and verbal communication skills for explaining cryptographic and architectural tradeoffs.
- Ability to operate with substantial autonomy in evolving technical and policy environments.
Workplace
- Hybrid role based in Austin, TX.
- Applicants progressing to the offer stage may be required to attend an in-person interview at a Cloudflare office or hub.
Skills
- Applied Cryptography
- Web PKI
- TLS
- X.509
- Merkle Tree Certificates
- ACME
- Certificate Transparency
- HSM
- Distributed Systems
- Security Engineering
