**ManTech** seeks a motivated and mission-focused **Senior Cyber Security Engineer** to join our team in **Herndon, Virginia** . In this role, you will contribute to a high-priority mission by designing, implementing, and maintaining secure cloud architectures on AWS and Azure. You will work closely with Solutions Architects, Cloud Engineers, customer stakeholders, and compliance officers to align systems with federal security requirements. This position offers an exciting opportunity for a cybersecurity professional with a strong technical background and hands-on experience supporting secure, classified environments. **Responsibilities include but are not limited to:** + Designing and implementing cybersecurity architectures and controls in compliance with NIST, DoD, and federal civilian guidelines. + Managing vulnerability assessment and remediation activities using tools such as Tenable, Qualys, or Nessus. + Engineering solutions for endpoint protection, network segmentation, and SIEM integration, including Splunk, Microsoft Sentinel, or ELK Stack. + Supporting the full Risk Management Framework (RMF) lifecycle, including system categorization, control selection, implementation, assessment, and continuous monitoring. + Configuring and maintaining a suite of security tools including firewalls, IDS/IPS, endpoint protection platforms, and encryption services. + Developing and updating comprehensive security documentation, such as System Security Plans (SSPs), Plans of Action and Milestones (POA&Ms), and incident response plans. + Collaborating with SOC and government teams to analyze and respond to security incidents. + Automating security monitoring, reporting, and compliance validation processes using scripting languages like PowerShell, Python, or Bash. **Minimum Qualifications:** + Bachelor’s degree in Cyber Security, Computer Science, or Information Security; or 4+ additional years of cybersecurity experience in lieu of a degree. + 5+ years of experience in cybersecurity roles, with a minimum of 3 years supporting federal or defense customers. + Demonstrated experience with: + NIST SP 800-53 and RMF processes + Endpoint Detection & Response (EDR) platforms + Firewalls, IDS/IPS, VPNs, and PKI + Security automation and scripting + Responding to POA&Ms + Proven success supporting Authority to Design (ATD), Authority to Operate (ATO), and FedRAMP or FISMA-compliant systems. + Strong technical understanding of operating systems (Windows/Linux), network protocols, and cloud platforms (AWS or Azure). **Preferred Qualifications:** + Industry certifications such as CISSP, CEH, GSEC, CASP+, or Security+. + Experience with: + FedRAMP High environments + SCAP compliance tools and STIG implementation + SIEM platforms including Splunk, Elastic, or Sentinel + Security engineering within CI/CD pipelines (DevSecOps) + Familiarity with DoD or IC customer environments and DISA STIGs. **Clearance Requirements:** + US Citizenship required. Must be located within the continental United States with the ability to obtain a security clearance. **Physical 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. ManTech International Corporation, as well as its subsidiaries proactively fulfills its role as an equal opportunity employer. We do not discriminate against any employee or applicant for employment. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran. If you are a qualified individual with a disability and require a reasonable accommodation to apply for a position with ManTech through its online applicant system, please email us at careers@mantech.com and provide your name and contact information.