Senior Security Engineer

Nansen surfaces the signal and creates winners in the future of finance. We're building a new way to trade: agentic, onchain, and fully integrated. From analytics to execution, we're the platform where investors find alpha and act on it.

The Opportunity
As we scale our product, staking operations, and AI-powered capabilities, security matters more than ever. We're hiring a Senior Security Engineer to strengthen our security posture across the entire engineering organisation. You'll work closely with the Head of Security and collaborate hands-on with engineering teams across the company to ensure that the systems we build are secure by design.

This is a generalist security role. You'll operate across application security, cloud infrastructure security, and organizational security practices. It's ideal for someone who thrives in a high-autonomy environment, is comfortable spanning multiple security domains, and wants to have outsized impact at a growing company.

What You'll Do
• Conduct security reviews of systems, architectures, and code — proactively identifying and addressing vulnerabilities.
• Serve as a go-to security advisor for engineering teams, helping them make secure design decisions.
• Define and implement security standards across cloud infrastructure, applications, and blockchain systems.
• Implement and maintain security tooling: vulnerability scanning, endpoint protection, SIEM, logging and monitoring.
• Secure CI/CD pipelines and deployment workflows from a security perspective.
• Secure internal AI tools and LLM integrations — from API key management and prompt injection prevention to evaluating the security implications of AI adoption across the organization.
• Manage and improve secrets management, key management, and access control practices across the organization.
• Define and maintain secure coding guidelines and security review processes for engineering teams.
• Collaborate with external providers on penetration tests and security audits, ensuring findings are prioritized and remediated.
• Participate in incident response: investigation, containment, root cause analysis, and post-incident improvements.
• Support compliance and audit readiness by implementing required security controls and maintaining documentation.

What We're Looking For
• Strong understanding of cloud security (AWS, GCP, or similar), container security, and network security fundamentals.
• Hands-on experience implementing and operating security tools (SIEM, vulnerability scanners, endpoint protection, cloud security tooling).
• Experience with secrets management, key management, and encryption best practices.
• Experience securing AI/LLM tooling, agent-based systems, and modern developer platforms.
• Familiarity with securing CI/CD pipelines and developer tooling.
• Solid understanding of compliance framew