Member of Technical Staff, Security Engineer

About Fleet

Fleet studies how environments produce intelligence. We believe intelligence is an emergent property of environmental pressures: the environment determines what capabilities develop, what behaviors survive, and what "good" looks like. We work with frontier labs on post-training across modalities, building benchmarks that expose where frontier models break, training recipes that close those gaps, and scalable oversight for long-horizon agents. Backed by Sequoia Capital, Menlo Ventures, BCV, and SV Angel.

About the Role

Fleet moves quickly because our team can trust the systems behind its work. As one of Fleet’s Security Engineers, you will own the security loop that makes that possible: seeing threats early, responding decisively, and turning every finding into a stronger system.

This is a hands-on, high-ownership role across Fleet’s cloud infrastructure and corporate systems. You’ll investigate alerts and security reports, lead the response when something matters, ship the changes that close the issue, and build automation that expands what a small security team can accomplish.

What You’ll Do

• See what matters. Build and tune high-signal detections across cloud infrastructure, identity, endpoints, and business systems.
• Lead the response. Investigate suspicious activity, contain threats, find root causes, and make Fleet stronger after every incident.
• Turn findings into fixes. Trace security reports and vulnerabilities through the systems they affect, ship durable remediations, and verify that they work.
• Harden the foundation. Strengthen cloud access, workloads, networking, secrets, telemetry, and deployment paths while preserving the speed of the teams that depend on them.
• Automate the function. Use agents, APIs, code, and workflows to accelerate detection, investigation, remediation, and verification.

What We’re Looking For

• Experience owning detection and response, cloud security, infrastructure security, or security engineering in production.
• The instincts of both an investigator and an engineer: you can follow evidence across logs, code, and infrastructure then turn what you learn into a lasting technical improvement.
• Strong understanding of cloud infrastructure, identity and access, networking, logging, containers, and modern application environments.
• Comfortable writing code, building integrations, and making changes through version-controlled infrastructure and configuration.
• Experience using AI tools and agents to build security capabilities that are fast, reliable, observable, and auditable.
• Strong judgment about blast radius, testing, rollout, monitoring, and rollback. You know how to raise the security bar while keeping the business moving.

Compensation

Full-time, on-site in San Francisco, CA.

Salary range: $200,000 - $400,000 USD annually, plus meaningful equity.