Senior Security Engineer

About the Role

Muon seeks a Senior Security Engineer to join our Security Engineering & IT team. The ideal candidate brings deep expertise across multiple security domains and can operate independently to protect Muon’s infrastructure, data, and people. You will own and advance our security posture across endpoints, networks, cloud environments, and identity systems while contributing to compliance efforts including NIST 800-171 and ITAR/EAR requirements.

This position is hybrid and requires working on-site in our San Jose, CA office three days per week or fully remote from an approved U.S. location.

Responsibilities

• Design, deploy, and manage endpoint security solutions (EDR/XDR) across macOS and Windows fleets, including policy tuning, alert triage, and incident response
• Own network security architecture including firewall rule management, IDS/IPS tuning, network segmentation, and VPN infrastructure
• Lead vulnerability management program — run scans, prioritize findings, coordinate remediation with engineering teams, and track closure metrics
• Administer and harden IAM systems (Okta, AWS IAM) including SSO integrations, conditional access policies, privilege access reviews, and lifecycle automation
• Develop an