Sr Systems Security Engineer

Sierra Nevada Corporation•Beavercreek, OH

3d•Hybrid

About The Position

The Senior Systems Security Engineer / Information System Security Manager (ISSM) is a dual-mode technical subject matter expert and program security lead responsible for the cybersecurity posture, compliance governance, and system accreditation of information systems in a complex defense program environment. The role combines hands-on vulnerability scanning, SIEM operations, STIG hardening, and system monitoring with leadership accountability for ISSO team development, ATO lifecycle management, compliance framework implementation, and representing program security posture to government stakeholders and Authorizing Officials. Both the technical and governance dimensions are essential to the role. The position leads the design and implementation of security infrastructure, manages complex security projects, provides strategic direction for security practices, and mentors junior engineers. It owns the program’s RMF/ATO strategy, develops and enforces security policies and procedures, trains and mentors ISSOs/ISSEs, coordinates with DCSA, DoD, IC, and government stakeholders, and briefs program security status at formal U.S. Government reviews. The role executes and oversees vulnerability management, security monitoring, configuration hardening, and incident response. The role is within SNC’s Intelligence, Surveillance & Reconnaissance, Aviation, and Security business area, which develops and integrates ISR and aviation systems and provides C4ISR capabilities including design, integration, testing, certification, training, and logistics support. Current/active Top Secret U.S. security clearance with SCI eligibility and U.S. citizenship are required. The position may involve occasional travel and an on-call incident-response rotation. Work may be in an office or hybrid environment.

Requirements

Bachelor’s degree in Systems Security, Network Engineering, Information Technology, or a related engineering discipline; relevant experience may substitute for the education requirement. Without a degree, at least 16 years of related experience is required; a higher-level relevant degree may substitute for experience.
At least 8 years of experience in IT security or a related field.
At least 8 years in a formal ISSM role, with direct ATO package ownership and government AO interface responsibility.
Deep expertise in cybersecurity principles and practices, including experience with NIST and ISO 27001 frameworks and standards.
Demonstrated personal execution of Tenable vulnerability scanning, including configuring scan policies, running credentialed scans, interpreting results, and building dashboards.
Hands-on Splunk SIEM experience developing correlation searches, dashboards, and security use cases; triaging alerts; and managing forwarder deployments.
Active DISA STIG application experience on live systems, including knowledge of finding categories, compensating-control documentation, and POA&M management.
Experience personally leading security-posture briefings at government security reviews, ARBs, or AO-level meetings.
Deep working knowledge of NIST SP 800-53 Rev. 5, including control families, tailoring rationale, control inheritance, and assessment procedures.
Demonstrated ownership of the RMF/ATO lifecycle, including development of SSPs, SARs, POA&Ms, and security assessment evidence packages for presentation to a government AO.
Working knowledge of DCSA DAAG requirements for classified information-system accreditation, including experience in a DCSA-governed program and coordination with DCSA field representatives.
Working knowledge of CMMC, including Level 2/3 practice domains, assessment objectives, and CUI protection requirements.
Experience authoring or substantially contributing to PPSM documentation and knowledge of port/protocol justifications, the DoD PPSM registry process, and enforcement mechanisms.
Hands-on proficiency with Nessus/Tenable.sc, Tenable dashboard creation, ELK Stack (Elastic/Kibana), Splunk SIEM, DISA STIGs/SRGs, eMASS/XACTA, RHEL/Linux, vSphere/VMware, GitLab/GitHub, Bash scripting, CPU/system architecture, PKI/certificate management, NIST 800-53 Rev. 5, RMF/ATO processes, DCSA DAAPM, CMMC Level 2/3, TEMPEST requirements, and PPSM creation.
Current/active Top Secret U.S. security clearance with SCI eligibility; U.S. citizenship is required for the clearance.
Ability to work primarily at a computer for extended periods.
Ability to lift up to 25 lbs occasionally.
Ability to participate in an on-call rotation for incident response.
Ability to work in an office or hybrid environment.

Nice To Haves

Active CISSP certification.
CISM, CASP+, or equivalent senior-level security certification.
IAM Level III or IAT Level III baseline certification per DoD 8570/8140; the posting lists this among preferred qualifications while describing it as required per the baseline.
GitLab Certified Associate or GitHub Advanced Security certification.
RHCSA or equivalent Linux administration certification.
Experience with enterprise Tenable Security Center deployment, including multi-scanner architecture, repository management, and organizational reporting hierarchy configuration.
Familiarity with cross-domain solutions and data transfer guard administration in classified multi-domain environments.
Experience implementing Zero Trust architecture in a DoD program context, including network segmentation, identity-based access enforcement, and micro-segmentation.
Proficiency in IT project management and understanding of PMI/PMP frameworks, including planning, monitoring, controlling, and risk management.
Working knowledge of JIRA for managing and tracking Earned Value tasks, schedule and cost performance, and workflow status.
Experience managing multidisciplinary RMF teams and conducting security assessments under DoDI 8510.01, NIST SP 800-53A, CNSSI 1253, and program-level authorization processes.

Responsibilities

Lead the design and implementation of security infrastructure.
Manage complex security projects and provide strategic direction for security practices.
Own the program’s RMF/ATO strategy and manage ATO lifecycle activities, including development of SSPs, SARs, POA&Ms, and security assessment evidence packages.
Execute and oversee vulnerability management, including vulnerability scanning and scan-result interpretation.
Conduct and oversee security monitoring, SIEM operations, configuration hardening, and incident response.
Personally apply DISA STIGs to live systems and manage STIG findings, compensating-control documentation, and POA&Ms.
Develop and enforce security policies and procedures governing the program environment.
Train and mentor ISSOs/ISSEs and junior engineers; support ISSO team development.
Coordinate with DCSA, DoD, IC, government stakeholders, and DCSA field representatives on security and accreditation matters.
Represent program security posture to government stakeholders and Authorizing Officials, including leading briefings at government security reviews, ARBs, or AO-level meetings.
Author and contribute to PPSM documentation and support port/protocol justification and PPSM processes.
Participate in an on-call rotation for incident response.