Principal Cybersecurity Engineer – Threat Detection & Infrastructure

Hermeus is an aerospace and defense technology company founded to radically accelerate air travel by delivering hypersonic aircraft. The company aims to develop hypersonic aircraft quickly and cost-effectively by integrating hardware-rich, iterative development with modern computing and autonomy. This approach has been validated through design, build, and test of the company’s first combined turbojet-ramjet engine and is now being scaled through its first flight vehicle program, Quarterhorse. Hermeus is also developing Darkhorse — an uncrewed hypersonic aircraft designed to deliver unique asymmetric capabilities to the warfighter.
Hermeus is currently seeking a mission-focused Principal Cybersecurity Engineer with deep expertise in threat detection, incident response, and vulnerability management—who’s also excited to grow their skill set in managing broader network infrastructure.
This role blends hands-on cyber defense operations with opportunities to work across routing, switching, and comms infrastructure supporting both enterprise and mission-critical systems.  You’ll be part of a small, agile team defending high-consequence environments, participating in red/purple team activities, leading incident response, and shaping the future of cybersecurity within a fast-moving tech environment. If you thrive at the intersection of cyber operations and core infrastructure—and want to work on systems that matter—this role is for you. 

Key Responsibilities

• Serve as a lead engineer for incident response, insider threat detection, and cyber forensics across multiple environments. 
• Analyze network telemetry and event data to detect and respond to threats in real time. 
• Configure, manage, and monitor firewall systems (Palo Alto), and grow into broader infrastructure including routers, switches, and comms paths. 
• Conduct vulnerability assessments, threat modeling, and risk analysis. 
• Work closely with Legal, HR, and Security for evidence gathering, legal hold execution, and investigations. 
• Test and evaluate emerging AI tools and models for misuse potential, data leakage, and exploitability. 
• Mentor junior analysts through hands-on pairing, shadowing, and knowledge sharing. 
• Help build, tune, and maintain threat detection tools and playbooks. 
• Participate in the hardening and monitoring of both enterprise and mission systems networks. 

Required Qualifications

• 15+ years of experience in cybersecurity with a focus on threat detection, IR, or signals/network analysis.
•  Deep understanding of network traffic analysis, adversary tradecraft, and endpoint/network forensics.
•  Hands-on experience with Palo Alto firewalls or equivalent NGFW platforms.
• Strong foundational knowledge of networking—protocols, switching, routing, and packet-level analysis.
• Willingness to expand into broader infrastructure work (e.g., Cisco/Juniper routers, layer 2/3 switches, VLANs, and network design/support).
• Experience supporting high-consequence or mission-critical environments (e.g., defense, aerospace, national security).
• TS/SCI with Polygraph, or ability to obtain and maintain. 

Preferred Qualifications

• Familiarity with AI security testing or prompt injection techniques. 
• Prior experience leading or contributing to red/purple team operations. 
• Comfortable analyzing and working with proprietary or non-standard protocols. 
• Background in military or intelligence community operations (NSA, CIA, etc.). 
• Industry certifications such as GPEN, GCIH, GCFE, CEH (even if expired). 

Working Conditions and Physical Requirements   Safety is paramount, with stringent protocols ensuring a secure workplace. Collaboration is key, providing opportunities to work closely with a skilled team dedicated to innovation.   This position requires the candidate be able to:  Work at elevated heights and in confined spaces. Lift up to 50 lbs. unassisted. Stoop, bend, crawl, and maneuver in tight spaces. Work outdoors, in all weather conditions.  
U.S. EXPORT CONTROL COMPLIANCE STATUS The person hired will have access to information and items subject to U.S. export controls, and therefore, must either be a “U.S. person” as defined by 22 C.F.R. § 120.62 or otherwise eligible for deemed export licensing. US persons include U.S. citizens, U.S. nationals, lawful permanent residents (green card holders), and asylees and refugees with such status granted, not pending. 
EQUAL OPPORTUNITYHermeus is an Equal Opportunity Employer. Employment decisions at Hermeus are based solely on merit, competence, and qualifications, without regard to race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.