Senior Security Engineer

As a Senior Security Engineer at Mysten Labs, you build and operate security infrastructure at scale for a team advancing foundational web3 technology. You own end-to-end security across detection, response, infrastructure hardening, and emerging tooling like LLM-driven automation, working on the systems that power Sui, Move, and the broader Mysten technology stack.

What you'll do

• Build and operate the Security Observability & Data Platform (tens of TB/month and growing), covering ingestion, normalization, retention, and the query and detection layer on top; detections are code: tested, reviewed, and measured for precision.
• Own endpoint security across the fleet: deploy, tune and respond with EDR; run and configure binary authorization; and set hardening baselines with IT Operations.
• Lead threat hunting, internal investigations and insider-threat work; handle security incidents end to end from triage, containment, forensics, root cause, to the control that prevents a repeat.
• Build the next generation of security services and run them in production: zero-trust AuthN/AuthZ, a uniform blocking service, an application proxy, asset inventory, developer portal, and compliance as code.
• Build and run the agent platform (local and Kubernetes), using LLM agents to automate triage, enrichment, investigation and response, with deterministic checks wherever a model's answer isn't enough.
• Review infrastructure and cloud designs (Kubernetes, AWS/GCP, bare metal, CI runners) for security, and help engineering teams adopt shared services instead of building their own.
• Run red-team and adversary-emulation exercises, and turn the results into detections and fixes.
• Write runbooks and post-mortems that someone who wasn't in the room can follow at 3 a.m.

What you bring

• A Bachelor's degree in Computer Science, Computer Engineering, a relevant technical field, or equivalent practical experience.
• 5+ years in security engineering, detection and response, or infrastructure/SRE with a security focus, including hands-on incident response on endpoints and in the cloud.
• Experience operating an EDR, writing and tuning detections; knowledge of macOS and Linux internals as attackers use them: persistence, credential theft, process injection, living-off-the-land binaries.
• Experience building or operating telemetry pipelines and a SIEM or security data lake at TB scale; strong SQL, including detection logic over large datasets.
• Hands-on production engineering: Linux, containers, Kubernetes, at least one major public cloud, infrastructure as code, monitoring and alerting.
• Proficiency in Python or Go, and comfort with Rust or willingness to work in it (most of Mysten's stack is Rust).
• Working knowledge of identity: SSO (OIDC/SAML), phishing-resistant MFA, device trust, and how session and token theft work.
• Strong written communication: can run an incident channel and write the post-mortem.
• Interest in the web3 space.

Nice to have

• Experience building zero-trust access, identity-aware proxies or policy engines.
• Binary authorization or allowlisting at fleet scale.
• Familiarity with the threat actors that target crypto companies and their methods, from social engineering and fake campaigns to supply chain compromises.
• Digital forensics (memory, disk, macOS unified logs) and malware analysis.
• Experience building security tooling with LLM agents (Claude Code skills or comparable), and a clear sense of where models help and where deterministic tooling has to do the work.
• Compliance as code (CIS benchmarks); experience in ISO 27001 or SOC 2 environments.
• Publications, conference talks or open-source security tooling.

About Mysten Labs

Mysten Labs builds foundational infrastructure and products to advance the internet through step-function improvements in what technology makes possible. The team works on on-chain finance and the emerging agent economy, building secure, scalable blockchain infrastructure through Sui, Move, and a broader technology stack.