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 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 Qualifications • 5+ years of experience in information security or security engineering roles • Strong hands-on experience with endpoint detection and response platforms (CrowdStrike, SentinelOne, or similar) • Demonstrated experience managing enterprise vulnerability scanning tools (Tenable, Qualys, Rapid7, or similar) • 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 Nice-to-Have Skills • 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 Salary The salary range for this role is $184,000 - $208,000, 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. About Muon Space Founded in 2021, Muon Space is an end-to-end Space Systems Provider that designs, builds, and operates LEO satellite constellations delivering mission-critical data. Our revolutionary, integrated technology stack enables customers to optimize every dimension of their missions for faster time-to-orbit and superior constellation remote sensing performance. Our state-of-the-art facility in the heart of Silicon Valley is optimized for manufacturing spacecraft and rapid, flexible payload integration at scale. From climate monitoring to national security, Muon Space is dedicated to delivering Earth Intelligence for a safer and more resilient world. Taking Care of Our Team At Muon salary is only part of our total compensation package. In addition to salary, full-time employees receive equity compensation as well as benefits including medical, dental, and vision insurance, a 401k retirement plan, short & long term disability and life insurance. We also offer three weeks paid vacation for new employees, along with 12 paid holidays, unlimited sick time and paid parental leave. Our mission embraces the entire planet and we believe our team should too. Muon is dedicated to creating a diverse and dynamic company and workforce. We believe in equal employment opportunity regardless of race, color, ancestry, religion, sex, age, national origin, citizenship, sexual orientation, marital status, disability, or gender identity. We value diversity in the workplace, and that starts with our applicants. We encourage you to apply, even if you don't check all the boxes, and we look forward to reviewing your application! In addition, if you need a reasonable accommodation as part of your application for employment or interviews with us, please let us know. ITAR/EAR Requirements This position requires access to export controlled information. To conform to U.S. Government export regulations applicable to that information, applicant must either be (A) a U.S. person, defined as a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (green card holder), (iii) refugee under 8 U.S.C. § 1157, or (iv) asylee under 8 U.S.C. § 1158, (B) eligible to access the export controlled information without a required export authorization, or (C) eligible and reasonably likely to obtain the required export authorization from the applicable U.S. government agency. The Company may, for legitimate business reasons, decline to pursue any export licensing process.