Director, Senior Security Architect

Bullish, Inc.; Greater London; Hybrid; GBP 120,000 - 180,000; Full time

Job summary

Bullish is seeking a Director, Senior Security Architect in London to lead security across web, API, mobile and trading platforms. This hands-on yet strategic role sits at the intersection of engineering and risk management, guiding threat modeling and secure design while mentoring teams to uphold high security standards.

Based in SoHo London, the role requires full-time onsite collaboration with product and infrastructure teams and a proven track record in security leadership within fast-paced,

Qualifications

• 10+ years in cybersecurity with 5+ years of hands-on coding experience.
• Strong threat modeling, pen testing, code reviews and security methodologies.
• Proficient in modern languages and platforms; able to translate risks to executives.
• Experience with cloud platforms (AWS, Azure or GCP) and Linux environments.
• Familiar with CI/CD security tooling and vulnerability management.

Responsibilities

• Build complex threat models for critical systems and establish industry-leading cybersecurity requirements.
• Partner with Product, Engineering and Infrastructure to ship secure software across web, API, mobile, FIX and trading platforms.
• Lead global security initiatives and build AI-powered tooling to scale the program.
• Assess vulnerability risks and deliver actionable recommendations with KPIs for exec reporting.
• Provide technical leadership and mentorship to cybersecurity and engineering teams.

Skills

Threat modeling

Penetration testing

Code reviews

Executive communication

Independent contributor

Tools

AWS

Azure

GCP

Linux

SAST

DAST

CI/CD security

Job description

## Director, Senior Security ArchitectApply: London: Full time: Posted Today: JR2001275## **About Bullish**## Bullish is an institutionally focused global digital asset platform that provides market infrastructure and information services. These include: **Bullish** **Exchange** – a regulated and institutionally focused digital assets spot and derivatives exchange, integrating a high-performance central limit order book matching engine with automated market making to provide deep and predictable liquidity. Bullish Exchange is regulated in Germany, Hong Kong, and Gibraltar. **CoinDesk** **Indices** – a collection of tradable proprietary and single-asset benchmarks and indices that track the performance of digital assets for global institutions in the digital assets and traditional finance industries. **CoinDesk** **Data** - a broad suite of digital assets market data and analytics, providing real-time insights into prices, trends, and market dynamics. **CoinDesk** **Insights** – a digital asset media and events provider and operator of Coindesk.com, a digital media platform that covers news and insights about digital assets, the underlying markets, policy, and blockchain technology.**Reports to:**CISO Americas**Position Overview**At Bullish, security is not a checkpoint, it is the foundation of trust that lets people move billions across our markets with confidence. The Bullish Security Architecture team secures Bullish Global, including the Bullish Exchange, Bullish Liquidity Services, CoinDesk Indices, CoinDesk Data, CoinDesk Media, and CoinDesk Events, designing the defenses that keep our mission-critical trading systems and other business lines resilient against the most capable adversaries in the world.As a senior member on this team, you will 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, and pushing our security bar beyond industry-leading. This is a senior technical leadership role, a hands-on application and cloud security architect who leads through influence, deep expertise, and mentorship.If you thrive on solving complex technical challenges in a fast-moving crypto landscape and building first-of-their-kind systems, this is where you will do the most impactful work of your career.This position is based in **SoHo London** and will be required to work **full-time onsite**.**Responsibilities:*** 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, 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 within a dynamic, fast-paced environment.* Provide technical leadership and mentorship to the cybersecurity and engineering teams.**Experience & Qualifications:*** 10+ years in cybersecurity, including 5+ years of hands-on coding, alongside deep expertise in threat modeling, pen testing, code reviews, and offensive security methodologies.* Strong foundation in network protocols (IP, DNS, HTTP, SSL/TLS), cryptography (PKI, encryption at rest/in motion), Linux environments, and public cloud platforms (AWS, Azure, or GCP).* Proficient in programming languages like C/C++, Java, JS, Python, Go, or Rust* Possess a 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.* A strong individual contributor with ability to drive projects independently from conception to complete with minimal oversight.**Nice to Have:*** A restless drive to secure systems and continuously learn new technologies.* Experience securing trading, financial-market, or other regulated, high-stakes systems.* Relevant certifications, such as security architecture certifications (e.g. SABSA, TOGAF), offensive security (e.g. OSCP, OSCE, SANS, CREST) and cloud security specialty certifications (AWS, Azure, or GCP).**Bullish is proud to be an equal opportunity employer. We are fast evolving and striving towards being a globally-diverse community. With integrity at our core, our success is driven by a talented team of individuals and the different perspectives they are encouraged to bring to work every day.**