Senior Security Engineer

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 our satellites, ground systems, mission networks, and cloud infrastructure while contributing to compliance efforts including NIST 800-171 and ITAR/EAR requirements. Aerospace security is the core of this role: you will secure satellite and flight software, embedded systems, command-and-control (C2) interfaces, ground systems, and the communication links that connect them.

This position may be fully on-site at our San Jose office, hybrid, or fully remote from an approved U.S. location.

• Design and implement cybersecurity controls for satellite software, ground systems, communication links, and mission infrastructure
• Develop secure software practices for mission systems, including threat modeling, code reviews, vulnerability management, and security testing
• Monitor mission networks and satellite systems for cyber threats, investigate incidents, and coordinate containment and recovery
• Collaborate with aerospace, software, systems, and compliance teams to ensure missions meet security, safety, and regulatory requirements
• Own network security architecture including firewall rule management, IDS/IPS tuning, network segmentation, and VPN infrastructure
• Assess vulnerabilities in flight software, embedded systems, command-and-control interfaces, and satellite communication protocols, and coordinate remediation with engineering teams
• Administer and harden IAM systems (Okta, AWS IAM) including SSO integrations, conditional access policies, privilege access reviews, and lifecycle automation
• Develop and maintain security monitoring and alerting using SIEM platforms, building detection rules and response playbooks
• Conduct security assessments of new tools, vendors, and architectural changes before deployment
• Drive cloud security posture management across AWS environments including IAM policies, S3 bucket security, security group reviews, and CloudTrail/GuardDuty monitoring
• Support CMMC Level 2 and NIST SP 800-171 compliance — maintain SSP control narratives, collect evidence, and prepare for assessments
• Develop and deliver security awareness training and phishing simulation campaigns
• Lead or support incident response activities including containment, forensic analysis, root cause determination, and post-incident reporting
• Maintain and improve data loss prevention (DLP) controls for CUI and sensitive data
• Contribute to security policy development and keep documentation current as the environment evolves

• 5+ years of experience in information security or security engineering roles
• Active TS/SCI clearance, or eligibility to obtain one
• Familiarity with satellite communication protocols, embedded systems, and RF or space-ground link security
• Experience securing aerospace or mission systems — satellites, ground systems, embedded/flight software, or command-and-control (C2) interfaces
• Experience with secure software practices — threat modeling, code review, security testing, and vulnerability management
• Deep understanding of identity and access management principles and hands-on Okta or Azure AD administration
• Proficiency with cloud security in AWS (IAM, VPC, Security Groups, CloudTrail, GuardDuty, Config)
• Experience with SIEM platforms (Splunk, Sentinel, Elastic, or similar) for log analysis and detection engineering
• Solid networking knowledge — firewalls, proxies, DNS security, network segmentation, packet analysis
• Familiarity with compliance frameworks such as NIST 800-171, CMMC, SOC 2, or ISO 27001
• Excellent written and verbal communication skills — able to convey risk and technical findings to both engineers and leadership

• Relevant certifications (CISSP, GIAC, CEH, AWS Security Specialty, or similar)
• Experience with infrastructure-as-code security (Terraform, CloudFormation) and CI/CD pipeline security
• Background in environments subject to ITAR/EAR export control requirements
• Experience supporting U.S. Government, DoD, or national security space programs

The salary range for this role is $154,000 - $207,000, plus a competitive equity grant and comprehensive benefits package. Final compensation will be determined based on skills, qualifications, experience, and geographic location as assessed during the interview process.