Senior Software Engineer

Job description

NextGen Federal Systems, LLC is seeking a Software Engineer with experience in Systems Tool Kit (STK) to support the development and integration of mission analysis and modeling applications. These applications enable multi-domain analysis—including air, space, ground, and maritime systems—by leveraging physics-based modeling and simulation to assess system performance, coverage, communications, and operational effectiveness. Responsibilities include software development, configuration, and execution; result interpretation; documentation; and modification and maintenance of tools and code. The selected candidate must be quick to learn, adaptable, and agile, interfacing directly with end-customers and customer leadership. The software engineer will provide a full range of systems and software engineering to support critical mission analyses. ### Responsibilities - Develop, customize, and maintain STK-based applications to support mission planning, analysis, and visualization - Integrate STK (Engine, Components, or Desktop) with external tools, models, and data sources to enable end-to-end mission workflows - Implement backend services using Python and support frontend interfaces as needed - Analyze and interpret simulation results, providing actionable insights to engineering teams and stakeholders - Support traceability between mission analysis outputs and system models, ensuring consistency across the digital engineering environment - Support deployment and execution of applications in modern environments (e.g., containerized or cloud-based) - Contribute to documentation, user guides, and technical deliverables - Troubleshoot and enhance existing tools to improve performance, usability, and scalability ### Qualifications - BS or equivalent in Computer Science, Engineering, Mathematics, or equivalent technical degree - 5+ years’ prior work experience in the aerospace or defense industry, with demonstrated software development experience - Experience customizing or automating STK-based tools or applications highly desired (including STK, STK Engine, STK Components, and/or Cesium) - Experience integrating tools via APIs (REST or similar) - Proficiency in Python and experience with backend frameworks such as Flask is required - Strong expertise in React JS for building modern and responsive user interfaces is highly desirable - Knowledge of version control systems, preferably Git is highly desirable - Proven experience as a Full Stack Developer or similar role is highly desirable - Capable of self-management and responsibly executing multiple tasks in accordance with priorities and deadlines - Active Top Secret (TS) clearance required (SCI eligibility preferred) ### Preferred Qualifications - Experience with STK Engine, STK Components, or Cesium - Experience linking STK analyses to MBSE environments (e.g., parameter passing, trade studies, digital thread integration) - Familiarity with digital engineering ecosystems, mission thread development, or model orchestration tools - Experience with Docker, cloud environments, or DevSecOps practices - Frontend development experience (e.g., React)