Spacecraft represent the most pressing unmet need across the entire aerospace industry. As more launch vehicles come online and the cost to orbit decreases, more companies launching payloads to space continue to emerge. For the first time in history, this influx of payload companies combined with reduced launch costs has resulted in a massive increase in need for commercial spacecraft platforms, known as satellite buses. These buses hold the payloads of our customers and are flown on launch vehicles. Apex manufactures these satellite buses at scale using a combination of software, vertical integration, and hardware that is designed for manufacturing. Our spacecraft enable the future of society: ranging from earth observation to communications and more. We’d love for you to join us on our mission of providing humankind access to the galaxy beyond our planet.  ABOUT THE ROLE Apex Space is seeking an RF Test Engineer to own system-level verification and performance testing of spacecraft communications hardware, with a primary focus on S-band TT&C and X-band payload systems. This role sits at the intersection of RF design, spacecraft integration, and hardware test, supporting development from early bring-up through spacecraft-level validation and environmental test campaigns. You’ll work closely with RF, avionics, software, AIT, and systems engineering teams to develop scalable RF test infrastructure, execute integrated verification campaigns, debug complex hardware issues, and help ensure our communications systems perform reliably in flight-like environments. This is a highly hands-on role focused on building, operating, and improving RF test systems for rapidly scaling spacecraft programs. Responsibilities: * Develop and execute system-level RF test strategies for spacecraft communications hardware and payloads. * Design RF test architectures and signal chain configurations for transmitter and receiver characterization, including loopback, end-to-end, and over-the-air test setups. * Lead RF performance verification activities across development, qualification, and production hardware. * Support spacecraft integration and environmental test campaigns including thermal vacuum, thermal cycling, vibration, EMI/EMC, and full vehicle integration testing. * Partner closely with RF design engineers, avionics teams, and systems engineers to debug anomalies, root cause failures, and drive hardware improvements. * Develop automated test scripts, infrastructure, and data collection tools to improve test efficiency and repeatability. * Coordinate RF test execution alongside AIT, environmental, and production teams to support aggressive spacecraft build schedules. * Define and maintain RF test procedures, verification plans, calibration methods, and test documentation. * Support design reviews, test readiness reviews, qualification campaigns, and customer-facing verification activities. * Specify, integrate, and maintain RF test equipment and lab infrastructure including analyzers, signal generators, channel emulators, antennas, and chamber assets. * Contribute to the development of scalable RF verification frameworks and long-term test infrastructure as Apex production volume grows. Requirements: * B.S. in Electrical Engineering, Physics, or related technical discipline. M.S. preferred. * 5+ years of hands-on RF test engineering experience, including experience with aerospace, satellite, or communications hardware. * Strong understanding of RF fundamentals, transmitter/receiver architectures, modulation schemes, and link-level testing. * Hands-on experience with RF measurement equipment including vector signal analyzers, spectrum analyzers, signal generators, noise figure analyzers, and related RF lab equipment. * Experience developing automated test software, scripting, or RF test infrastructure (Python preferred). * Experience supporting hardware bring-up, integration, debug, and environmental testing activities. * Ability to troubleshoot RF hardware and system-level issues down to the board, subsystem, or interface level. * Strong understanding of RF verification methodologies, test execution, and production test practices. * Experience writing clear test procedures, verification plans, and technical reports. * Ability to operate effectively in fast-paced hardware development environments with high ownership and autonomy. * Strong communication and cross-functional collaboration skills. Nice to Haves: * Experience with spacecraft communications systems, TT&C architectures, or payload RF systems. * Familiarity with GEVS, MIL-STD, ECSS, CCSDS, or EMI/EMC testing standards. * Experience supporting spacecraft-level integration and environmental qualification campaigns. * Experience with channel emulators, anechoic chamber testing, or over-the-air RF validation. * Familiarity with production test scaling, automated validation systems, or high-rate hardware manufacturing environments. WHY JOIN APEX? Apex believes in creating a work environment that you look forward to embracing every day. Our employees love working at Apex, and we want you to love it too. We're a fast-growing startup that has raised more than $500M in funding, and we invest heavily in our people from day one. WHAT WE OFFER FOR FULL-TIME EMPLOYEES: * Shared upside: Receive equity in Apex, letting you benefit from the work you create * Best-in-class healthcare: 100% company-paid medical, dental, and vision for you and your dependents, plus $100k life insurance at no cost * Comprehensive PTO package to reset and recharge - starting at 15 days vacation, growing to 20+ days annually, plus 10 paid holidays * Competitive 401(k) plan with generous matching - 100% match on first 3%, 50% on next 2% * 8 weeks paid parental leave plus childcare reimbursement up to $350/day for work-related travel * Daily catered lunch and unlimited snacks to keep you fueled throughout the day * Vibrant community: Monthly office socials, pickleball tournaments, run club, and gatherings for you and your family * Your dream desk setup and all the tools you need to be your most productive self * World-class Playa Vista office with the benefit of in-person collaboration with amazing coworkers and flexibility to integrate work and life * Real impact opportunity: Work alongside experts from aerospace, new space, and other cutting-edge industries to make a lasting difference Ready to join a team where your contributions matter and your future is bright? Let's build something extraordinary together. EQUAL OPPORTUNITY EMPLOYER Apex Technology, Inc. is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Candidates and employees are always evaluated based on merit, qualifications, and performance. We will never discriminate on the basis of race, color, gender, national origin, ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.