As a Senior Propulsion Development Engineer at Inversion, you will design, build, and test liquid and gas propulsion systems for our next-generation Arc hypersonic reentry vehicle, with an emphasis on Attitude Control System (ACS) thrusters, fluid feed systems, and propulsion components. You will own the mechanical design and analysis of fluid networks, manage hardware fabrication, author test plans, procedures, and reports, and lead hot-fire test campaigns. You will work cross-functionally with structures, avionics, software, and test teams to physically integrate propulsion hardware into the vehicle and verify system performance against mission requirements.