Senior Software Engineer/Technical Lead with Security Clearance

Position Title: Senior Software Engineer / Technical Lead - Digital Twin & Modeling/Simulation Location: Herndon, Virginia Clearance Requirements: Top Secret clearance or eligibility to obtain and maintain a U.S. Government security clearance

Pay Rate: $60.00 per hour; contract-to-hire conversion target of $130,000-$140,000 annually

Position Description: Seneca Resources is seeking a hands-on Senior Software Engineer / Technical Lead to lead the development of advanced Digital Twin, Modeling and Simulation, and 3D visualization capabilities supporting mission-critical federal operations. This role will guide the evolution of a C#/.NET simulation platform that integrates discrete event simulation (DES), agent-based modeling (ABM), and Unity 3D visualization.

The successful candidate will provide technical leadership to software engineers, shape platform architecture, engage with government stakeholders, and advance simulation capabilities toward real-time digital twins powered by live operational data. The position supports a high-visibility Homeland Security mission focused on port-of-entry operations and requires regular onsite work in Herndon, Virginia, with occasional travel to government facilities.

Key Responsibilities

• Lead the architecture and integration of discrete event, agent-based, and hybrid simulation engines with Unity 3D environments.
• Design reusable interfaces for simulation state streaming, simulation-time and render-time synchronization, replay, and 3D visualization.
• Advance visualization of operational metrics, including queues, throughput, wait times, and resource utilization.
• Lead research and development efforts to evolve simulation platforms into real-time digital twins.
• Design data integration, calibration, and validation approaches using sensors, IoT devices, telemetry, streaming feeds, and other live operational data.
• Build prototypes, integration code, and production-ready software using C#/.NET.
• Review code, establish engineering standards, and provide technical direction across architecture, development, testing, releases, and maintenance.
• Lead, mentor, and develop C# simulation engine and Unity engineering teams.
• Establish best practices for model verification and validation, statistical analysis, replication, convergence, sensitivity analysis, version control, and configuration management.
• Translate customer and operations research requirements into maintainable, scalable, and extensible software solutions.
• Present technical architectures, digital twin roadmaps, and model capabilities to government and executive stakeholders.
• Support technical demonstrations, white papers, proposals, and business development initiatives for federal simulation and digital engineering opportunities.
• Travel periodically to customer facilities to observe and assess the operations being modeled.

Top Requirements

• Bachelor's degree in Computer Science, Engineering, Information Systems, or a related technical discipline.
• At least 7 years of professional software development experience.
• At least 5 years of experience designing or architecting simulation software at the engine or framework level, including Discrete Event Simulation (DES), Agent-Based Modeling (ABM), or hybrid simulation.
• Demonstrated hands-on Digital Twin experience connecting simulation or virtual models to real-world data, including sensors, IoT, telemetry, or streaming feeds.
• Strong C#/.NET development experience with the ability to define architecture, review code, and build prototypes and integration solutions.
• Proven experience directly leading, mentoring, and providing technical direction to software developers.
• Experience engaging directly with government customers, executive stakeholders, or federal program leadership.
• Ability to obtain and maintain a U.S. Government security clearance; an active Top Secret, Secret, or Public Trust clearance is preferred.
• Excellent communication, presentation, collaboration, and technical leadership skills.
• Ability to work onsite in Herndon, Virginia and travel periodically to government facilities.

Preferred Qualifications

• Experience with Unity or Unreal Engine, including 3D visualization, simulation-state integration, and performance optimization.
• Experience with Kafka, MQTT, time-series databases, or other streaming and IoT data pipeline technologies.
• AR/VR development experience, including Unity XR.
• Proficiency with Python or R for statistical analysis and simulation input/output processing.
• Experience supporting federal technical demonstrations, proposals, capture efforts, or business development.
• Experience with model verification and validation, operations research, statistical output analysis, or digital engineering.

About Seneca Resources At Seneca Resources, we are more than just a staffing and consulting firm, we are a trusted career partner. With offices across the U.S. and clients ranging from Fortune 500 companies to government organizations, we provide opportunities that help professionals grow their careers while making an impact. When you work with Seneca, you're choosing a company that invests in your success, celebrates your achievements, and connects you to meaningful work with leading organizations nationwide.

We take the time to understand your goals and match you with roles that align with your skills and career path. Our consultants and contractors enjoy competitive pay, comprehensive health, dental, and vision coverage, 401(k) retirement plans, and the support of a dedicated team who will advocate for you every step of the way. Seneca Resources is proud to be an

Equal Opportunity Employer, committed to fostering a diverse and inclusive workplace where all qualified individuals are encouraged to apply.