Senior PKI & Cryptographic Systems Engineer

WebHosting; Austin, Northern (TX, KY); Hybrid; USD 150,000 - 210,000; Full time

Benefits offered by this job

Equity plan

Job summary

Cloudflare is hiring a Senior Software Engineer for PKI & Cryptographic Systems in a hybrid model across Austin, London, or Lisbon. You will design and build the cryptographic infrastructure, manage certificate lifecycles, and ensure secure key handling at scale.

You will work at the intersection of applied cryptography, distributed systems, and security engineering, shaping Cloudflare’s PKI stack for the post-quantum era and large-scale operations.

Qualifications

• 5+ years of production systems software experience, with a strong operational track record.
• Familiarity with HSMs; PKCS#11 integration, key ceremonies, and key attestation flows.
• Strong systems programming background in Go, Rust, or C/C++.
• Distributed systems fluency with globally replicated, high-availability services.
• Experience designing and operating database schemas for high-integrity systems (Postgres or equivalent).
• Security-hardened system design instincts–threat modelling, defence in depth, least privilege.

Responsibilities

• Own the cryptographic core; integrate with HSMs via PKCS#11 and SDKs; build key lifecycle tooling.
• Automate ACME-based issuance, renewal pipelines, and short-lived certificate rotation.
• Instrument transparency with Certificate Transparency, tamper-evident logs, and audit pipelines.
• Maintain compliance with CA/B Forum, WebTrust, and root store programs; participate in audits.
• Represent Cloudflare in the WebPKI community; publish CA incident reports.
• Ship the post-quantum future; contribute to PQ encryption and authentication work.
• Own code end-to-end from design to production incident response; ensure observability and SLOs.
• Partner with SSL/TLS product teams and data-center infrastructure teams.

Skills

Cryptography

Go / Rust / C/C++

Distributed systems

HSM PKCS#11

Post-quantum crypto

Tools

OpenSSL

CFSSL

PostgreSQL

Job description

Cloudflare is hiring a Senior Software Engineer for PKI & Cryptographic Systems in a hybrid model across Austin, London, or Lisbon. You will design and build the cryptographic infrastructure, manage certificate lifecycles, and ensure secure key handling at scale.

You will work at the intersection of applied cryptography, distributed systems, and security engineering, shaping Cloudflare’s PKI stack for the post-quantum era and large-scale operations.