Senior C++ Engineer, Key Management

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 team

The KMS team sits at the very heart of Fireblocks’ platform and is a pivotal team in the company.

The team is responsible for the cryptographic backbone of the platform that secures customers’ most sensitive secrets. Every transaction signing flow. Every cosigner interaction. Every key generation ceremony. Every backup and recovery mechanism. If it touches a private key - it touches this team.

The team performs mission-critical engineering at high scale, working on systems where failure is not an option, security is existential, performance matters and correctness is everything. The work is deep, challenging, and intellectually demanding - blending modern C++ systems programming with distributed backend architecture and applied cryptography.

If you enjoy solving problems where security, scale, distributed systems, and adversarial thinking collide - this is your kind of challenge.

What You'll Do:

You’ll collaborate with backend engineers, infrastructure teams and security and cryptography researchers to ship production-grade highly secure digital signing systems, balancing cryptographic rigor, performance constraints, and distributed reliability in a domain where small mistakes have massive consequences. This includes:

Architecting, designing and implementing distributed backend services responsible for key generation, storage and lifecycle management

Developing high-assurance signing protocols and signing flows (utilizing MPC or external signing devices)

Building secure backup and disaster recovery mechanisms for cryptographic material

Hardening systems against adversarial conditions and real-world attack vectors

Optimizing performance-critical components that execute complex operations

What You'll Bring:

5+ years of strong C++ experience in production systems

Experience building large-scale backend or distributed systems (SaaS experience strongly preferred)

Experience working with distributed SQL DBs

Experience working with cloud and backend technologies (e.g. Docker, K8S, AWS, Azure, DataDog, Prometheus)

Deep understanding of concurrency, memory management, system design, and performance optimization

Experience working on mission-critical or high-reliability platforms

A strong security engineering mindset

Strong Advantage

Experience with cryptography, MPC, threshold signatures, or key management systems

Familiarity with blockchain technologies

Experience with confidential computing technologies

Experience integrating with HSMs or secure enclaves

Background in highly security-sensitive environments

Fireblocks' mission is to enable every business to easily and securely access digital assets and cryptocurrencies. In order to do that, we strongly believe our workforce should be as diverse as our clients, and this is why we embrace diversity and inclusion in all its forms.

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