Director, Senior Security Architect

As Director, Senior Security Architect at Bullish, you will lead the security architecture function for Bullish Global, including the Bullish Exchange, Bullish Liquidity Services, CoinDesk Indices, CoinDesk Data, CoinDesk Media, and CoinDesk Events. You sit at the intersection of cutting-edge engineering and high-stakes finance, shaping how secure software is built across web, API, mobile, and FIX platforms. Reporting to the CISO Americas, this is a senior technical leadership role combining hands-on application and cloud security architecture with mentorship and influence across engineering teams. This position is based in SoHo, London and requires full-time onsite work.

What you'll do

• Build complex threat models for critical systems and establish industry-leading cybersecurity requirements to turn ambiguity into clear, prioritized defenses
• Partner closely with Product, Engineering, and Infrastructure teams to design and ship secure software across web, API, mobile, FIX, and trading platforms
• Lead complex global security initiatives and build custom AI-powered tooling to maximize efficiency and scale the cybersecurity program
• Assess vulnerability risks, deliver actionable recommendations across all technical levels, and track health metrics and KPIs for executive reporting
• Drive high-impact projects and adapt to evolving business needs
• Provide technical leadership and mentorship to the cybersecurity and engineering teams

What you bring

• 10+ years in cybersecurity, including 5+ years of hands-on coding, alongside deep expertise in threat modeling, code reviews, and offensive security methodologies
• Solid working knowledge of Linux environments, including command-line proficiency, shell scripting, system hardening, and security configuration
• Hands-on experience in penetration testing
• Strong foundation in network protocols (IP, DNS, HTTP, SSL/TLS), cryptography (PKI, encryption at rest and in motion), and public cloud platforms (AWS, Azure, or GCP)
• Proficiency in programming languages such as C/C++, Java, JavaScript, Python, Go, or Rust
• Deep understanding of common vulnerability frameworks (OWASP Top 10, SANS CWE Top 25)
• Solid grasp of enterprise software development, Agile, CI/CD pipelines, and security tooling (SAST, DAST, OSA, Vulnerability Management, API traceability)
• Excellent ability to convey complex technical risks to non-technical executives and engineers and build strong cross-functional partnerships
• Strong individual contributor who can drive projects independently from conception to completion with minimal oversight

Nice to have

• Current holder of Offensive Security Certified Professional (OSCP) certification
• Experience securing trading, financial-market, or other regulated, high-stakes systems
• Additional relevant certifications such as security architecture certifications (SABSA, TOGAF), offensive security certifications (CISSP, OSCE, SANS, CREST, CISM), or cloud security specialty certifications (AWS, Azure, or GCP)
• A restless drive to secure systems and continuously learn new technologies

About Bullish

Bullish is an institutionally focused global digital asset platform providing market infrastructure and information services. The company operates Bullish Exchange, a regulated spot and derivatives exchange in Germany, Hong Kong, and Gibraltar; CoinDesk Indices, a collection of proprietary and single-asset benchmarks; CoinDesk Data, a suite of market data and analytics; and CoinDesk Insights, a digital media platform covering digital assets, markets, policy, and blockchain technology.