Protocol Security Engineer

At Matter Labs, we believe freedom drives progress and prosperity. We don’t see ourselves as a company, but as a team aligned around a single mission: to advance personal freedom for all (see ZK Credo).To achieve this goal, we’re building zkSync — a credibly neutral, fully open source technology stack and network on top of Ethereum, which is owned and governed by its community. We use advanced cryptography called zero-knowledge proofs to scale Ethereum infinitely without compromising on security or decentralization. With a world-class team, a community of over 1M supporters across Twitter + Discord, and hundreds of millions $ in funding, we have abundant resources to accomplish the mission.Job Description: Protocol Security EngineerWe are seeking a Protocol Security Engineer to join our Security Team. This role blends hands-on security work with the opportunity to influence protocol security from the earliest stages of development. You’ll focus on safeguarding ZKsync’s core components—smart contracts, ZK circuits, and blockchain nodes—while staying at the forefront of security research and industry best practices.This role is ideal for someone who is curious, thrives on breaking systems, and wants to apply that mindset ethically in a high-stakes environment.What You’ll Be DoingIntentionally breaking things — conducting threat modeling and internal reviews of Solidity contracts, blockchain state transition functions (Rust), and other critical systemsTracking the latest hacks, exploits, and attack vectors across the industry, and translating lessons learned into actionable security improvementsEmbedding security best practices across development teams and influencing secure designTaking ownership of protocol components with a focus on secure architecture and implementationParticipating in security investigations and incident response, often under time-sensitive and high-pressure conditionsWhat We’re Looking ForCuriosity & hacker mindset — you want to know how things break, not just how they workStrong security instincts with the ability to anticipate adversarial behaviorsFamiliarity with recent security incidents in the blockchain space and knowledge of prevention techniquesPractical experience with Solidity smart contracts, ZK circuits, or core blockchain protocols (preferred but not required)Comfort with protocol-level debugging and root-cause analysisProficiency in strongly typed languages (e.g., C++, Scala, Go); Rust and Solidity are our primary languages, but prior experience with them is not mandatoryDeep understanding of algorithms, data structures, and their computational/memory complexitiesExperience implementing data structures and algorithms from scratchFluent written and spoken English