ECS is seeking a Systems Engineer to work in our Arlington, VA office / remote. The Systems Engineer will support a large-scale federal IT modernization initiative focused on transforming legacy systems into secure, scalable, and resilient enterprise solutions. This role combines systems design, integration, cloud engineering, and technical leadership to ensure mission-critical systems meet evolving federal requirements. The Systems Engineer will work closely with cross-functional teams, including cybersecurity, data, DevSecOps, and program management, to architect and deliver modern technology capabilities that improve operational efficiency, user experience, and compliance with federal standards.