Application Security Engineer

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 Application Security team at Fireblocks treats security as a high-stakes engineering discipline, not an administrative task. We are looking for an Adversarial Builder to lead the defense of our Global Application Landscape—securing everything from our core SDLC and Software Supply Chain to our enterprise-wide AI adoption.
In this hands-on role, you will:

• Engineer, Don’t just triage: Move beyond manual reviews to build code-driven detection logic and custom AI agents that automate vulnerability hunting, triaging and remediation.
• Security by design: Partner with R&D teams (including Infra and DevOps) to define the application-level technical guardrails for internal and external-facing products.
• Scout the Frontier: Act as an early adopter of state-of-the-art systems, evaluating and integrating cutting-edge tech from frontier security startups in AI and Cloud Runtime security.

This role demands a practitioner who thinks like an attacker, possesses a developer’s urge to automate, and has the broad landscape understanding to connect dots across complex, modern domains.

What You’ll Do

• Promote Enterprise-Grade Security Initiatives: Engineer and scale the security strategy for Fireblocks’ entire product ecosystem, spanning both internal infrastructure and external-facing products. You will ensure code security at scale by hardening the SDLC, securing the Software Supply Chain perimeter, and designing the technical guardrails for AI adoption at both the enterprise and product levels.
• AI Solutions Builder: scale our security program using AI-driven tools. You will develop and fine-tune autonomous agents to handle complex code analysis, vulnerability hunting, and automated remediation.
• Drive Early Adoption of Frontier Tech: Act as a scout and evaluator for the world’s most innovative security startups. You’ll partner with cutting-edge vendors in emerging fields like AI Security and Cloud Runtime Security, ensuring Fireblocks remains an early adopter of state-of-the-art defensive systems.
• Scale Through Engineering: Move beyond manual reviews. You’ll manage and extend AppSec tools to eliminate false positives and build custom logic that reflects our unique codebase.
• Collaborative Engineering: Work alongside our in-house DevOps team to rapidly deploy custom security tools at an enterprise grade.

What You’ll Bring

You’re a Great Fit If...

• You see a manual task and immediately think about how to automate it with a script or an LLM.
• You enjoy the challenge of securing industry-novel risks that don't have a "best practice" handbook yet.
• You value simplicity in design and believe that security should be a developer enabler, not a blocker.
• You thrive in fast-paced environments where "status quo" is a dirty word.

Why You’ll Love It Here

• Ownership: You’ll have the autonomy to propose and lead high-impact security initiatives.
• Cutting-Edge Stack: Work with the latest in AI, blockchain infrastructure, and cloud security.
• A "Rapid" Culture: Our in-house DevOps capability means your tools get deployed and scaled across the enterprise in days, not months.
• Mentorship & Growth: Collaborate with world-class experts in cryptography and cybersecurity who are committed to your professional evolution.