Sr Cyber Security Engineer

Constellis is seeking a Senior Cyber Security Engineer to bridge compliance and engineering for its LEXSO platform. The role owns cybersecurity activities end-to-end, leads DoD RMF and Authority to Operate efforts, embeds security automation into CI/CD pipelines, hardens microservices and infrastructure, and reports cybersecurity risks and remediation progress to leadership.

Responsibilities:

• Own the LEXSO cybersecurity program end-to-end – from gap identification through architectural design to implementation tracking
• Report cyber risk posture and remediation progress; translate technical findings into terms leadership can act on
• Define and maintain the cybersecurity requirements backlog and progress-tracking cadence
• Lead the technical execution of the RMF process to achieve and maintain Authority to Operate (ATO) for the LEXSO platform
• Implement security controls in accordance with NIST SP 800-53 and DoD SRG/STIGs
• Generate and maintain artifacts required for eMASS, including SSPs, POAMs, and SARs
• Conduct self-assessments using ACAS (Nessus) and SCAP Compliance Checker (SCC) to identify vulnerabilities
• Integrate automated security testing (SAST/DAST) tools (e.g., SonarQube, OWASP ZAP) into the GitLab/GitHub CI/CD pipeline
• Develop scripts (Python, Bash, Ansible) to automate patching and configuration management for Linux (RHEL/Ubuntu) servers
• Implement Container Security scanning for Docker/Kubernetes environments to detect vulnerabilities before deployment
• Enforce "Security as Code" principles using Terraform or Helm charts
• Analyze vulnerability scan results and write the code/scripts to remediate findings (e.g., fixing SSH configurations, patching libraries, hardening NGINX)
• Harden APIs and microservices by implementing secure authentication (OAuth2/JWT/mTLS) and encryption standards (FIPS 140-2)
• Respond to zero-day threats and CVEs by rapidly deploying hotfixes to the production environment
• Conduct threat modeling sessions with the engineering team to identify attack vectors in the multi-sensor architecture
• Design and implement secure logging and auditing pipelines (ELK Stack/Splunk) to meet audit requirements
• Advise on the secure architecture for integrating third-party sensors (LiDAR, Radar) and IoT devices
• Work is typically based in a remote working environment and subject to frequent interruptions. Business work hours are Monday-Friday from 8:00 am to 5:00 pm, however some extended or weekend hours may be required
• Other duties as assigned

Requirements:

• 8+ years of experience in Cyber Security Engineering or DevSecOps
• Proven track record of achieving ATO (Authority to Operate) for a software system in a DoD/Federal environment
• Hands-on experience with RMF, NIST 800-53, and DISA STIGs
• Proficiency in scripting languages (Python, Bash) for automation
• Experience with vulnerability scanning tools (ACAS/Nessus, SonarQube, Burp Suite)
• Strong knowledge of Linux Security (SELinux, iptables, hardening)
• Experience with CI/CD tools (GitLab CI, Jenkins) and Container Security (Docker/K8s)
• Demonstrated ability to work autonomously — identify security gaps, drive architectural design decisions, and track implementation through to completion
• Experience communicating technical findings and program status to executive leadership; able to translate risk and remediation into terms leadership can act on
• Track record of ownership over requirements definition and progress reporting for cybersecurity workstreams
• CISSP, CASP+, or Security+ CE (Required)
• Active Secret Security Clearance
• Bachelor's degree in Computer Science, Cyber Security, or related technical discipline
• Experience securing cloud environments (AWS GovCloud / Azure Government)
• Experience with FedRAMP authorization processes
• Familiarity with "Zero Trust" architecture principles
• Previous experience as a Software Developer before moving into Security
• Prior experience as a technical lead or senior individual contributor with direct exposure to stakeholders