Freelance Battery Modeling Simulation Engineer Jobs in California

CHAOS Industries is redefining modern defense with a multi-product portfolio that gives the ultimate advantage-domain dominance. The company's products are powered by Coherent Distributed Networks (CDN), empowering warfighters, commercial air operators, and border protection teams to act faster, adapt rapidly, and stay ahead of evolving threats. 

CHAOS Industries was founded in 2022 and has raised a total of $1 billion in funding from leading investors, including 8VC, Accel, and Valor Equity Partners. The company is headquartered in Los Angeles, with offices in Washington, D.C., San Francisco, San Diego, Seattle, and London. For more information, please visit www.chaosinc.com.

About the Team:

The Modeling & Simulation team builds the simulation capabilities used to design, integrate, test, and validate advanced aerospace and defense systems. We develop physics-based models, simulation environments, and analysis tools that help engineering teams evaluate system behavior, improve designs, and reduce risk before hardware design, integration, test, and fielding.

About the Role:

As a Modeling & Simulation Engineer, you will develop and maintain simulations for complex systems and subsystems across vehicle, sensor, software, and hardware domains. You will work with engineering teams to select the right model fidelity, build credible simulation environments, analyze results, and validate models against test data. The team owns simulation capabilities across CHAOS's product portfolio, from fast-running engineering models to high-fidelity closed-loop simulations, with model fidelity matched to the decision, test event, or verification objective.

This role requires strong technical judgment, software ability, and engineering fundamentals. You will help shape simulation architecture, model interfaces, validation workflows, and the tools used to support design trades, integration, test planning, and system verification.

What You'll Do:

• Develop, integrate, and maintain models and simulations for advanced defense systems, including sensors, vehicles, effectors, environments, autonomy software, embedded software, and hardware interfaces.
• Build system- and subsystem-level simulations to support design trades, performance assessment, integration, test planning, verification, field-test preparation, and post-test analysis.
• Develop models of RF/radar, EO/IR, communications, seekers, navigation sensors, vehicles, actuators, environments, targets, and other system elements at appropriate levels of fidelity.
• Support simulation environments such as software-in-the-loop (SITL), hardware-in-the-loop (HITL), hardware/software integration labs (HIL/SIL), real-time simulation, discrete-event simulation, automated regression testing, Monte Carlo studies, and large-scale batch analysis.
• Work with RF, EO/IR, sensors, GNC, autonomy, flight software, embedded software, systems engineering, test, and product teams to define simulation requirements, interfaces, assumptions, and validation criteria.
• Run sensitivity, uncertainty, design-of-experiments, and performance studies to characterize system behavior and inform engineering decisions.
• Validate and correlate models against analytical references, lab data, calibration data, ground test, flight test, range data, hardware test, field data, or other authoritative sources.
• Develop and maintain simulation software, model APIs, configuration systems, scenario definitions, data pipelines, analysis tools, visualization workflows, and automated validation tests.
• Integrate embedded software, autonomy software, flight software, sensor models, hardware models, or subsystem models into closed-loop simulation environments.
• Produce clear technical documentation, model assumptions, validation evidence, analysis summaries, engineering-review material, customer briefings, and CDRL-supporting content.
• Help establish best practices for model development, simulation credibility, software quality, version control, reproducibility, model review, and regression testing.

Experience in every area below is not expected; candidates with depth in one or more relevant modeling and simulation domains are encouraged to apply.

Required Qualifications:

•  Bachelor's degree in engineering, computer science, physics, applied mathematics, or a related technical field, or equivalent demonstrated expertise.
• 5+ years of experience developing, integrating, validating, or using models and simulations for complex technical systems.
• Strong programming ability in one or more relevant languages or environments such as Python, C++, C, Rust, MATLAB/Simulink, or similar.
• Strong fundamentals in engineering, physics, mathematics, numerical methods, software development, or data analysis.
• Experience analyzing simulation outputs, test data, telemetry, sensor data, or engineering data sets to support technical decisions.
• Experience with modern software development practices such as Git, code review, automated testing, issue tracking, CI/CD, and reproducible workflows.
• Ability to work independently, make sound technical judgments, document assumptions clearly, and collaborate across engineering disciplines.
• Eligibility to obtain and maintain a Top Secret / Sensitive Compartmented Information clearance.

Preferred Qualifications:

• Master's degree in engineering, computer science, physics, applied mathematics, or a related technical field.
• Experience with physics-based modeling, digital twins, dynamic-system simulation, sensor simulation, or system performance modeling.
• Experience developing models or simulations in one or more relevant domains such as RF/radar, EO/IR, communications, seekers, flight dynamics, GNC, controls, autonomy, aerodynamics, propulsion, embedded systems, or hardware interfaces.
• Experience with RF, radar, EO/IR, or communications modeling, including measurement generation, signal, noise, and propagation effects, environmental effects, clutter, detection performance, tracking performance, calibration assumptions, scene generation, or uncertainty modeling.
• Experience with 6-DOF simulation, coordinate frames, numerical integration, vehicle dynamics, actuators, navigation sensors, or environmental models.
• Experience developing or integrating SITL, HITL, HWIL, real-time, closed-loop, discrete-event, or distributed simulation environments, including DIS, TENA, HLA, or similar frameworks.
• Experience integrating embedded software, autonomy software, flight software, sensor models, hardware models, or subsystem models into simulation environments.
• Experience with Monte Carlo simulation, uncertainty quantification, design of experiments, sensitivity analysis, or large-scale simulation execution.
• Experience correlating models against lab, ground, flight, range, hardware, or field-test data.
• Experience with deterministic, high-performance, parallel, or large-scale simulation frameworks.
• Experience building simulation APIs, scenario generation tools, configuration systems, data pipelines, analysis tooling, visualization workflows, or automated regression tests.
• Experience with MBSE, requirements traceability, model-based development, model validation, simulation credibility, or verification evidence.
• Experience supporting DoD, DARPA, AFRL, ONR, MDA, NAVAIR, DEVCOM, intelligence community, or advanced commercial technology programs.
• Active TS/SCI clearance.

Why CHAOS?

• Health Benefits: Medical, dental, and vision benefits 100% paid for by the company
• Additional benefits: 401k (+ 50% company match up to 6% of pay), FSA, HSA, life insurance, and more
• Our Perks: Free daily lunch, 'No meeting Fridays', unlimited PTO, casual dress code
• Compensation Components: Competitive base salaries, generous pre-IPO stock option grants, relocation assistance, and (coming soon!) annual bonuses
• Team Growth: 250 employees and counting across 5 global offices

The stated compensation range reflects only the targeted base compensation range and excludes additional earnings such as bonus, equity, and benefits. If your compensation requirements fall outside of the range, we still encourage you to apply. The salary range for this role is an estimate based on a range of compensation factors, inclusive of base salary only. Actual salary offer may vary based on (but not limited to) work experience, education and/or training, critical skills, and/or business considerations. 

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