Simulation Engineer - TS​/SCI

Description

The Mission Solutions Business Area at Leidos has an opening for a Simulation Engineer in Reston, Virginia. The primary focus of the work is systems simulation related to reverse engineering Weapons of Mass Destruction (WMD) related facilities. Candidate must bring a creative, yet sound, approach to identifying and solving challenges where all the information desired is inherently unavailable and have exceptional attention to detail and a commitment to thoroughness.

The successful candidate will work as a member of an interdisciplinary team of government and contractor personnel. Work will be performed in a fast-paced, high-energy environment within a government facility.

• Design, develop, evaluate, validate, verify, analyze critical infrastructure related simulations (e.g. electric power, HVAC, building control systems) to understand their interactions and to uncover vulnerabilities. Simulation types include: system of systems simulations, distributed simulations, and object-oriented simulations
• Design, build, and maintain efficient, reusable, and reliable codes and models
• Collaborate with teams of engineers and developers, participating in regular code reviews
• Perform integration testing as well as collaborating with other internal teams
• Communicate with project customers or end users to fully understand, plan, and implement feedback and feature requests

• Candidate MUST possess an active TS/SCI, or a Top Secret clearance with a current SSBI, and be eligible to obtain a TS/SCI w/ poly level clearance. US Citizenship is REQUIRED.
• BS degree and 8+ years of prior relevant experience or MS with 6+ years of prior relevant experience.
• Must have a degree in simulation engineering, systems engineering, data science, operations research or a related field
• Experience with system of systems modeling and simulation

• Working knowledge of MATLAB, VENTSIM, COLE, or SCEPTRE software
• Working knowledge of heating and ventilation systems, thermodynamics and airflow, electric power systems, industrial, building, or process control systems.
• Professional experience in Unity, Unreal, or other 3D development.
• Working knowledge of REACT, JavaScript, Python, C++, C#.
• Knowledge of Scrum/Agile development framework.
• Experience working with cloud computing platforms such as AWS.
• Experience with implementing and maintaining unit testing.
• Proficiency with Git or comparable version control system.
• Knowledge of 3D modeling software (Blender, Maya, etc.) and ability to manipulate 3D geometry.
• Familiarity with applications being deployed to build AR/VR environments and applications such as Unity 3D and Visual Studio.
• Dev Sec Ops  experience
• Machine Learning experience

Original Posting:
September 24, 2025

Pay Range: $ - $

Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended January 3, 2025. For more information, visit

Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available at

Beware of fake employment opportunities using Leidos' name. Leidos will never ask you to provide payment-related information during any part of the employment application process (i.e., ask you for money), nor will Leidos ever advance money as part of the hiring process (i.e., send you a check or money order before doing any work). Further, Leidos will only communicate with you through emails that are generated by the  automated system - never from free commercial services (e.g., Gmail, Yahoo, Hotmail) or via Whats App, Telegram, etc.

If you received an email purporting to be from Leidos that asks for…