Cybersecurity Engineer - ISSO

SAIC; St. Louis (MO); On-site; USD 120,000 - 150,000; Full time

Job summary

SAIC is seeking a Cyber Security Engineer to support critical DoD and Intelligence Community missions in St. Louis.

You will lead RMF assessment and authorization, vulnerability management, and secure operations for classified systems, coordinating with DevSecOps and engineering teams to maintain compliance and incident readiness. Role requires TS/SCI clearance with polygraph, a bachelor’s degree plus 5 years of experience (or equivalent), and hands-on RMF/ATO documentation in XACTA/eMASS.

Qualifications

• Active TS/SCI clearance; willing to pass polygraph.
• Bachelor's degree plus 5 years of experience (or equivalent).
• Hands-on RMF, POA&Ms, ATO documentation experience.
• Experience with ACAS and IAVM tracking.
• Knowledge of STIGs, patching, and system hardening.
• Familiarity with NIST publications and incident-response processes.
• Strong analytical and communication skills.

Responsibilities

• Execute RMF processes for Assessment & Authorization (A&A).
• Develop/maintain SSPs, POA&Ms, SARs, and ATO artifacts in XACTA/eMASS.
• Conduct vulnerability scanning and track remediation using ACAS/IAVM.
• Implement and validate NIST 800‑53 and CNSSI 1253 controls.
• Support hardening, patching, STIG compliance for Windows, Linux, and networks.
• Monitor systems and assist with incident response.
• Evaluate security impacts of system changes.
• Collaborate with engineering, administration, and DevSecOps teams.

Skills

Analytical skills

Communication skills

Scripting experience

Education

Bachelor’s degree

Tools

Jira

Confluence

ACAS/IAVM tracking

XACTA

eMASS

Job description

Job ID 2615385

Location

St. Louis, MO, US

Date Posted

2026-08-07

Category

Cyber

Subcategory

Cyberspace Ops

Schedule

Full-Time

Shift

Day Job

Travel

Yes - 10% of the time

Minimum Clearance Required

TS.SCI_wPoly

Clearance Level Must Be Able to Obtain

None

Potential for Remote Work

ORA_ON_SITE

Description

SAIC is seeking a Cyber Security Engineer to support critical DoD and Intelligence Community missions. You will lead assessment, authorization, vulnerability management, and secure operations for classified systems.

Responsibilities

• Execute RMF processes for Assessment & Authorization (A&A).
• Develop/maintain SSPs, POA&Ms, SARs, and ATO artifacts in XACTA/eMASS.
• Conduct vulnerability scanning and track remediation using ACAS/IAVM.
• Implement and validate NIST 800‑53 and CNSSI 1253 controls.
• Support hardening, patching, STIG compliance for Windows, Linux, and networks.
• Monitor systems and assist with incident response.
• Evaluate security impacts of system changes.
• Collaborate with engineering, administration, and DevSecOps teams.

Qualifications

Required Qualifications

• Active TS/SCI clearance. Candidates must have this clearance to be considered.
• Willing and able to pass a polygraph.
• Bachelor’s degree + 5 years of experience (or equivalent).
• Active or Current TS/SCI.
• DoD 8570 IAT II+ (Security+, CySA+, CISSP, etc.).
• Hands‑on RMF, POA&M, ATO documentation experience.
• Experience with ACAS, IAVM tracking.
• Knowledge of STIGs, patching, system hardening.
• Familiarity with NIST publications and incident‑response processes.
• Strong analytical and communication skills.

Desired Qualifications

• Scripting experience (Python, Java, React).
• DevSecOps pipeline experience.
• Linux/Windows, databases, or web app experience.
• Familiarity with Agile tools (Jira, Confluence).
• Experience with NIST SP 800‑171.