Software Engineer, C++ Simulations (Starlink)

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today SpaceX is actively developing the technologies to make this possible, with the ultimate goal of enabling human life on Mars. SOFTWARE ENGINEER, C++ SIMULATIONS (STARLINK) As a C++ Simulation Software Engineer on the Starlink GNC team, you will take a leading role in architecting, refactoring, redesigning, and building high-performance C++ core infrastructure for our in-house vehicle dynamics simulator and additional simulation environments. This includes dispersed Monte Carlo simulations, hardware-in-the-loop (HITL) setups, testing frameworks, support tooling, and GNC-specific data visualization. You will own the design and evolution of the simulation backbone—driving major refactors and new designs that scale performance and capability with our growing constellation—while collaborating on high-fidelity multi-body physics models, environmental perturbations, and vehicle power/propulsion/control hardware representations. This is a high-impact opportunity for expert C++ engineers who thrive on complex, performance-critical systems (think game engine-level simulation and high-performance computing challenges applied to real spacecraft). You will work across engineering groups to deliver the high-fidelity simulations that enable cutting-edge software and hardware development. SpaceX seeks motivated C++ specialists who love tackling hard technical problems, excel in dynamic environments, and prioritize clean, efficient, maintainable code and software best practices. RESPONSIBILITIES: Lead the design, major refactors, redesigns, and ongoing evolution of the core C++ vehicle dynamics simulator and associated testing/support infrastructure for Starlink, ensuring it scales in performance and capability with the constellation. Architect and improve high-performance C++ Monte Carlo simulation infrastructure, including parallelization, dispersion handling, and reliability for large-scale runs. Drive development of new simulation features, models, and tooling in collaboration with users—focusing on performance, usability, and extensibility of the C++ core. Own performance optimization, profiling, continuous integration, unit/integration testing, and reliability improvements across the simulation stack. Design and implement new testing frameworks, support infrastructure, and visualization components to accelerate GNC development. Collaborate cross-functionally to accurately model multi-body physics, environmental effects, and hardware behaviors while maintaining rigorous software quality. BASIC QUALIFICATIONS: Bachelor’s degree in a STEM discipline and 1+ years of software development experience; OR 4+ years of professional software development experience in performant C++ OR numerical simulations PREFERRED SKILLS AND EXPERIENCE: Expert-level C++ skills focused on writing performant, simple, and safe code: strong command of the language fundamentals, efficient memory management, multi-threading/concurrency, data-oriented design, and careful performance-oriented implementation (favoring straightforward, low-overhead solutions over complex abstractions or heavy STL use when they compromise speed or safety). Experience building or optimizing high-performance simulations, physics engines, or real-time systems (e.g., game engines, multi-body dynamics, robotics, or aerospace simulators). High-performance computing (HPC) background: parallel computing, multi-threading, profiling/optimization tools, scalable architectures, or related techniques (Monte Carlo, distributed sims, etc.). Strong communication skills and the ability to proactively coordinate with partner teams—essential for success in a role that largely serves and collaborates closely with other engineering groups. Strong software design and architecture skills, especially for large-scale, maintainable C++ systems; experience leading…