Senior Engineer, Transaction 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.

We are looking for a Senior Engineer to build and scale security infrastructure for our Transaction Threat Protection team, protecting customer transactions in real time.

This role sits at the intersection of high-volume transaction security and decentralized finance (DeFi), requiring an engineer who balances deep technical execution with a strong product mindset.

What You’ll Do

• Systems Architecture: Design and maintain scalable, secure cloud infrastructure capable of processing high-velocity financial data.
• Security Engineering: Develop automated systems to detect and mitigate threats within both traditional payment flows and DeFi protocols (Smart Contracts/Web3).
• AI-Augmented Development: Integrate the latest AI tools (e.g., Claude Code, Cursor, Copilot, LLM-based analysis) into your workflow to increase engineering velocity and security coverage.
• Product Ownership: Partner with product teams to ensure security features provide a seamless user experience without compromising safety.
  
  

• Cloud & Web Expertise: Extensive experience building and deploying production-grade applications on major cloud providers (AWS/GCP/Azure).
• Full-Stack Proficiency: Strong background in modern web development frameworks and a deep understanding of web security protocols.
• Modern Tooling: High proficiency with AI-assisted coding and automated testing tools. You see AI as a core component of the modern development lifecycle.
• Product Orientation: Ability to move beyond "code-to-spec" and contribute to the product roadmap based on technical feasibility and user impact.
• [Optional] DeFi Knowledge: Experience with, or a strong technical interest in, the security challenges unique to DeFi and blockchain ecosystems.
  
  

• High Stakes: You are building the primary defense for users' assets in both traditional and decentralized systems.
• Engineering Culture: We prioritize clean architecture, automated testing, and the adoption of cutting-edge development tools.
• Autonomy: You will own major components of the security stack from design through to production.