SMX is seeking a highly experienced **Information Systems Security Engineer (ISSE) – Sr** to support a mission-critical federal program in Washington, DC. This individual will serve as a senior cybersecurity and security engineering professional responsible for designing, implementing, assessing, and maintaining security controls that protect enterprise systems, applications, and infrastructure supporting critical mission operations. The selected candidate will function as a senior technical expert supporting multiple cybersecurity initiatives, authorization efforts, and security engineering activities. This role requires extensive experience in Risk Management Framework (RMF) implementation, security architecture, vulnerability management, security testing, and system authorization activities. The ideal candidate will possess strong technical leadership capabilities and the ability to evaluate security risks, develop mitigation strategies, and guide engineering teams in implementing...