Senior Security Engineer, DeFi

Mysten Labs is hiring a Senior Security Engineer to protect the Sui DeFi ecosystem: uncovering vulnerabilities, building monitoring tools, and assessing economic risk across DeFi protocols, including Mysten's own DeepBook, working closely with external protocol teams.

• Build and run continuous monitoring for security and economic risk (oracle issues, bad debt, liquidation capacity, accounting reconciliation, invariants)
• Extend security tooling, including static analysis and proprietary agent skills
• Drive compliance with DeFi security recommendations across supported protocols (audits, custody, upgrade governance, oracle dependencies)
• Hunt for critical vulnerabilities in highest-TVL Sui protocols (full audits, fork variant analysis, multisig upgrade review, incident forensics)
• Act as point of contact for external DeFi teams and Mysten's own DeFi products
• Write clear, actionable findings, reports, and runbooks

• 3+ years security engineering / smart contract security / DeFi risk engineering with real-world track record (audits, bug bounties, published research, incidents)
• Strong understanding of DeFi mechanics and failure modes (lending, AMMs, perps, liquid staking, oracles, flash loans, MEV)
• Proficiency in TypeScript and Python; comfort with Rust
• SQL over large datasets; experience with blockchain indexers/data warehouses
• Ability to read smart contract code at source/bytecode level; Move/Solidity/Rust experience transfers
• Rigor verifying claims against bytecode/chain state

This role sits at the center of Sui's DeFi security posture, pairing proactive vulnerability hunting on the ecosystem's highest-TVL protocols with the monitoring and tooling needed to catch economic risk before it becomes an incident.