Security Assessor/ATO Lead

Imagineeer is a fast-growing SBA 8(a) Small Disadvantaged Business headquartered in Arlington, VA, delivering federal AI modernization across health, defense, homeland security, and transportation. We design, test, and deploy secure, AI-ready systems that move agencies from pilots to production without breaking governance, compliance, or mission continuity. Our Mission Studio model creates shared environments where policy, data, security, and operations come together. We are capability-driven and competitive by design, not program-dependent. Our leadership has operated inside the federal systems we now transform, bringing institutional knowledge that accelerates delivery and reduces risk. If real delivery motivates you more than slides, and you want your work to compound across programs and agencies, Imagineeer is growing and we are building the team to match.

About the role

Imagineeer is seeking a Security Assessor/ATO Lead to assess vendors' FedRAMP packages and prepare agency authorization packages for commercial acquisition tools piloted by a federal civilian department. Authorization packages are built during the pilot from each vendor's FedRAMP inheritance so the agency's production decision is never waiting on contractor work.

You will own the security and authorization readiness checkpoint in the firm's decision methodology.

Key Responsibilities

• Define security requirements for candidate tools and the pilot environment.
• Assess candidate vendors' FedRAMP packages, including SSP, SAR, POA&M, and inherited controls.
• Prepare the agency authorization package for each piloted tool and complete an integration security review.
• Support agency security reviews of the contractor sandbox.
• Ensure the team meets the client's security requirements for contractors, including CUI handling under 32 CFR Part 2002 and NIST SP 800-171.
• Own authorization timing risk and validate security content in every deliverable.
• Lead the Security Analyst.
• Vendor FedRAMP authorization packages (SSP, SAR, POA&M)
• The contractor-provided sandbox in a FedRAMP-authorized cloud region, with mock AMS/PRISM, FPDS-NG, and SAM.gov interfaces and synthetic data

Qualifications and Skills

• Bachelor's degree in cybersecurity, computer science, or a related field.
• 10 or more years of information security experience, including leading federal security assessments and ATO efforts.
• Experience as a FedRAMP 3PAO assessor or equivalent depth in FedRAMP package review.
• CISSP, plus CISM or CISA.
• Expert knowledge of NIST RMF (SP 800-37) and SP 800-53.
• Ability to pass the client's contractor security vetting and obtain and maintain a PIV credential; this role may carry a higher position risk designation.
• The contractor-provided sandbox in a FedRAMP-authorized cloud region, with mock AMS/PRISM, FPDS-NG, and SAM.gov interfaces and synthetic data

Desired Skills and Competencies

• Experience as a FedRAMP 3PAO Lead Assessor.
• All three of CISSP, CISM, and CISA.
• Experience authorizing commercial SaaS for federal agencies.
• Experience with CUI programs and NIST SP 800-171 compliance.

Additional Information

Employment for this position is contingent upon the candidate being a United States citizen and having the ability to successfully obtain and maintain a Public Trust clearance, in accordance with applicable federal regulations. We use AI to review resumes. All hiring decisions will be made in compliance with applicable federal, state, and local laws and regulations

Equal Opportunity Employer

We are an Equal Opportunity Employer and do not discriminate in employment decisions on the basis of race, color, religion, sex (including pregnancy, sexual orientation, or gender identity), national origin, age, disability, genetic information, veteran status, or any other status protected by applicable federal, state, or local laws. All employment decisions are based on business needs, job requirements, and individual qualifications.