SMX is seeking a highly motivated **Information Systems Security Engineer (ISSE) – Mid** to support a mission-critical federal program in Washington, DC. This individual will support the design, implementation, assessment, and continuous improvement of security controls across enterprise information systems and technology environments. The selected candidate will work closely with system owners, cybersecurity personnel, engineers, architects, and government stakeholders to ensure systems meet federal cybersecurity requirements while supporting mission objectives. The ideal candidate will possess experience supporting Risk Management Framework (RMF) activities, security engineering, vulnerability management, security testing, and system authorization efforts within complex federal environments. This role requires strong technical and analytical skills with the ability to evaluate security risks, implement mitigation strategies, and contribute to the secure operation of mission-critica...