Protocol Security Engineer

As a Protocol Security Engineer at Matter Labs, 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. You own internal security reviews of critical components, threat modeling, adversary research, and the security side of incident response, with broad license to spot gaps and fix them beyond any assigned list. This is a hands-on individual contributor role for someone who wants to know how things break and applies that instinct ethically where the stakes are high.

What you'll do

• Break things on purpose by threat-modeling and reviewing Solidity contracts, blockchain state transition functions in Rust, and other critical systems before an attacker gets the chance.
• Own protocol components, taking responsibility for the secure architecture and implementation from design review through production.
• Track the adversary by following hacks, exploits, and new attack vectors across the industry and converting lessons into concrete improvements in the systems you protect.
• Scale security through others by embedding secure-design practice across development teams and influencing architecture decisions early.
• 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 (prior experience with Rust and Solidity is not required).
• 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.
• A long-term token incentive paid in ZK tokens, with new-hire grants vesting over four years and a one-year cliff.
• Fully remote work with occasional travel to team gatherings and industry events.
• Freedom and ownership culture with no time tracking (where legally applicable) and minimum bureaucracy, focus on results only.

About Matter Labs

Matter Labs builds private settlement infrastructure for regulated institutions to settle directly with each other without exposing data or ceding control. The core product, Prividium, gives each institution its own private settlement environment with independent governance and built-in interoperability. Founded in 2018, backed by a16z and Union Square Ventures, the company is a fully remote team of around 70 with eight years of production zero-knowledge infrastructure behind it.