Protocol Security Engineer

As a Protocol Security Engineer at Matter Labs (zkSync), you protect the core of ZKsync: smart contracts, ZK circuits, and blockchain nodes. Your reviews, threat models, and incident work determine whether vulnerabilities are found by your team or by attackers. This is a hands-on individual contributor role for someone who wants to understand how systems break and applies that knowledge ethically where the stakes are high.

What you'll do

• Threat-model and review Solidity contracts, blockchain state transition functions in Rust, and other critical systems before attackers find vulnerabilities
• Take responsibility for the secure architecture and implementation of protocol components you adopt, from design review through production
• Follow hacks, exploits, and new attack vectors across the industry and convert lessons into concrete improvements in zkSync's systems
• Embed secure-design practice across development teams and influence architecture decisions early, without formal authority
• Apply modern AI systems to scale security work, while accounting for attackers using the same tools
• Join security investigations and incident response, often under time pressure with incomplete information

What you bring

• A demonstrated record in security engineering or security research: threat modeling, security-focused code review, or vulnerability research on production systems, with findings you can walk through mechanism by mechanism
• Proficiency in strongly typed languages such as C++, Go, or Scala
• Deep grounding in algorithms and data structures, including their computational and memory complexity, with experience implementing them from scratch
• Protocol-level debugging and root-cause analysis on complex distributed systems
• Working knowledge of recent security incidents in the blockchain space and the prevention techniques behind them
• Clear written and spoken English, the company's working language

Nice to have

• Hands-on experience with Solidity smart contracts, ZK circuits, or core blockchain protocols
• Public security research, audit reports, bug-bounty results, or CTF history

What we offer

• Competitive base salary with no geographic pay discounts
• Performance-based variable compensation with a defined annual target, paid in ZK tokens or cash
• Long-term token incentive paid in ZK tokens, with new-hire grants vesting over four years and a one-year cliff
• Fully remote, with occasional travel to team gatherings and industry events
• Freedom and ownership culture: no time tracking where legally applicable, minimum bureaucracy, results-focused

About Matter Labs

Matter Labs builds Prividium, private settlement infrastructure that lets regulated institutions settle directly with each other without exposing data, ceding control, or waiting days. Founded in 2018 and backed by a16z and Union Square Ventures, the team is fully remote with around 70 people and eight years of production zero-knowledge infrastructure experience.