ManTech seeks a motivated, career and customer-oriented Security Engineer to join our team in Herndon, VA to design, implement, and maintain secure environments that align with compliance standards in support of a high priority mission at one of our National Intelligence Customers.This role requires an individual with a strong technical foundation in cybersecurity, a deep understanding of federal security frameworks, and a proactive approach to protecting mission-critical systems.Responsibilities include but are not limited to:Implement and maintain cybersecurity solutions across classified and unclassified environments.Perform risk assessments, vulnerability scans, and system hardening in compliance with NIST 800-53 and RMF.Support the preparation and submission of security documentation for Authority to Develop (ATD) and Authority to Operate (ATO) under IC guidelines.Collaborate with system owners, ISSOs, ISSEs, ISSMs, engineers, and auditors during security assessments and continuous monitoring.Monitor and respond to security incidents, performing root cause analysis and remediation.Integrate security controls into DevSecOps pipelines and cloud architectures (AWS, Azure, GCP or Oracle).Support development and implementation of security policies, plans, and SOPs.Stay current on evolving federal cybersecurity directives, threats, and compliance requirementsMinimum Qualifications:Bachelor’s degree OR 4+ years of additional equivalent experience a related field7+ years of experience in cybersecurity or related IT security rolesExperience with NIST Risk Management Framework (RMF), FedRAMP, or DoD Cybersecurity Maturity Model Certification (CMMC)Hands-on experience working in air-gapped Cloud environmentsKnowledge of system/network security principles and incident response practicesExperience supporting the Intelligence CommunityPreferred Qualifications:DoD 8570.01-M IAT Level II or III certification (e.g., Security+, CISSP, CEH, CISM)Knowledge of STIGs, SCAP tools, and secure system baseliningHands-on experience with security tools (e.g., ACAS, Splunk, Tenable, Palo Alto, CrowdStrike, or similar)Scripting or automation experience (Python, Bash, PowerShell) to support security operationsClearance Requirements:Must have active TS/SCI with Full Scope PolygraphPhysical Requirements:Must be able to remain in a stationary position 50% of the time.Needs to occasionally move about inside the office to access file cabinets, office machinery, etc.Frequently communicates with co-workers, management, and customers, which may involve delivering presentations. Must be able to exchange accurate information in these situations.