Senior Software Engineer, Platform Security

The world of digital assets is accelerating in speed, magnitude, and complexity, opening the door to new ways for leveraging the blockchain. Fireblocks’ platform and network provide the simplest and most secure way for companies to work with digital assets and it trusted by some of the largest financial institutions, banks, globally-recognized brands, and Web3 companies in the world, including BNY Mellon, BNP Paribas, ANZ Bank, Revolut, and thousands more.

About the Role

The Platform Security team sits at the core of the Fireblocks platform. We are responsible for the engine that evaluates, enforces, and governs every action taken within the system. If it involves a governance policy, an approval chain, or access control, it touches our team.

We are looking for a strong, ownership-driven Senior Software Engineer to lead our Policy Engine and Governance domain. You will perform mission-critical engineering at high scale, where correctness is everything. This role requires a true "builder", someone who can architect complex, distributed business logic while also having the technical depth and willingness to dive into low-level C++ code to optimize core platform components.

What You’ll Do

• Own the Domain: Take end-to-end technical ownership of the Policy Engine and Governance domain, driving the architecture, design, and implementation from 0 to 1 and beyond.
• Bridge High-Level & Low-Level: Navigate seamlessly between designing highly available, modern microservices and writing/maintaining performance-critical, low-level C++ code when the system demands it.
• Build for Scale: Implement robust backend applications to process complex rule evaluations at scale and with minimal latency.
• Collaborate & Lead: Act as a technical leader within the team, collaborating closely with Product, and other engineering teams to translate complex enterprise governance requirements into scalable technical solutions.
• Maintain Excellence: Ensure the robustness and maintainability of our services, taking part in incident response, on-call rotations, and operational excellence.
• Leverage AI: Utilize modern AI tools and agents to accelerate development workflows, while applying critical judgment to validate AI-generated output in complex or high-stakes contexts.

What You’ll Bring

Must-Have:

• 8+ years of backend engineering experience building large-scale, high-volume distributed systems or SaaS platforms.
• Polyglot & Systems Depth: Strong proficiency in modern backend languages (e.g., Go, TypeScript, Python, or Java) combined with hands-on experience and a willingness to touch low-level C++ code.
• Architectural Mastery: Deep understanding of system design, microservices architecture, concurrency, and distributed SQL databases.
• Builder's Mentality: A proven track record of taking deep ownership of a complex product domain, acting as a technical anchor, and pushing projects forward independently.
• AI Tooling Experience: Hands-on experience working with AI development tools (Claude Code, Cursor, etc.) and the critical engineering judgment to know when to trust and when to override them.
• Infrastructure Knowledge: Experience working with cloud and backend technologies (e.g., Docker, Kubernetes, AWS, DataDog).

Strong Advantage:

• Security Mindset: A background in cyber-security, adversarial thinking, or experience working in highly security-sensitive environments.
• Governance Expertise: Experience building Policy Engines, Rule Engines, Identity and Access Management (IAM) systems, or authorization frameworks.
• Blockchain Knowledge: Familiarity with the blockchain ecosystem, smart contracts, or digital assets.