Bachelor's degree in Systems Engineering, Computer Science, Computer Engineering, Software Engineering, Information Technology, Electrical Engineering, Mathematics, Physics, or a related field.16+ years of experience designing, integrating, and supporting enterprise systems, cloud architectures, and API-driven solutions within complex mission environments.5+ years of experience implementing and administering API gateway technologies in cloud-based architectures; Experience designing secure APIs and enterprise integration solutions utilizing REST, GraphQL, event-driven architectures, message queues, streaming platforms, or ETL pipelines. TITLE: Principal Systems Engineer (API Gateway)LOCATION: Sterling, VA (Relocation assistance considered)CLEARANCE REQUIRED: Active TS/SCI with CI PolyEMPLOYMENT TYPE: Full-time, Onsite POSITION SUMMARYModern Government Solutions (MGS) is seeking a Principal Systems Engineer to architect, integrate, and secure mission-critical API ecosystems supporting next-generation national security capabilities.