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 We’re looking for a Hardware Test Engineer to join our growing avionics test team. In this role, you’ll focus on hardware integration and testing, system-level and component-level test rack planning and buildup, avionics validation, and automated spacecraft test execution. You’ll work closely with electrical, mechanical, RF, and systems engineers to build and operate integrated spacecraft test environments, execute qualification campaigns, and troubleshoot flight hardware throughout development and integration. This role is highly hands-on and ideal for engineers who are ready to lead technical work independently, enjoy working directly with flight hardware and integrated test environments, and want to grow their impact beyond individual execution. RESPONSIBILITIES: Technical Work * Own the build, configuration, and maintenance of bus-level and/or component-level test racks * Lead hardware integration activities including harnessing, fixturing, rack integration, and mechanical/electrical interface validation * Own troubleshooting of flight hardware and test setup failures using laboratory instrumentation including oscilloscopes, multimeters, power supplies, DAQ systems, VNAs, and vector signal analyzers/generators * Support Flatsat operation and maintenance activities as needed * Execute and document functional checkouts, acceptance testing, environmental screening, and integrated system validation * Support environmental and qualification campaigns including EMI/EMC, vibration, thermal cycling, and TVAC * Execute RF and avionics validation testing for antennas, radios and transceivers, GNSS systems, LNAs and PAs, RF switches, and couplers and power dividers * Perform near-field antenna testing, cable loss characterization, S-parameter measurements, and insertion loss analysis * Support RF testing in thermal vacuum environments, including understanding of corona and multipactor considerations Documentation * Own test setup documentation including test setup diagrams, bills of materials (BOMs), harnessing documentation, and configuration records for component- and bus-level test racks * Author and maintain Design Verification Plans (DVPs), procedures, and test documentation Project Leadership * Own medium cross-functional or large function-specific avionics test projects end-to-end, from planning through closeout * Execute to an agreed plan, proactively identifying risks and resolving blockers * Coordinate partner teams across electrical, mechanical, RF, and systems engineering to keep integration and test campaigns on track * Provide structured updates and input at key project milestones, communicating status clearly to both technical and non-technical stakeholders * Collaborate with cross-functional teams on design-for-test initiatives and spacecraft integration campaigns Mentorship * Informally mentor and develop junior engineers on technical skills, test practices, and hardware integration workflows * Review junior engineer work products such as test procedures and documentation, providing constructive technical feedback REQUIRED QUALIFICATIONS: * Bachelor’s degree in Electrical Engineering, Aerospace Engineering, Physics, or related field * 5+ years of professional experience in aerospace hardware or electronics testing * Hands-on experience with laboratory instrumentation and hardware bring-up * Familiarity with avionics hardware and embedded communication protocols: * UART * SPI * CAN * I2C * Experience troubleshooting integrated electrical systems and test setups * Strong understanding of hardware integration and validation workflows * Excellent problem-solving and communication skills * Must be a U.S. Person (U.S. Citizen or Green Card holder) in accordance with ITAR requirements PREFERRED QUALIFICATIONS: * Experience integrating or testing spacecraft, launch vehicles, or flight electronics * Familiarity with RF communications systems and RF lab equipment * Experience with: * Harnessing * Fixturing * Environmental testing * Vibration testing * Familiarity with coaxial cable selection and RF interconnect characterization * Exposure to fast-paced aerospace production or integration environments * Experience designing PCBs or supporting hardware prototyping * Background conducting sensor functional tests, leak checks, or avionics channelization * Basic Python or scripting experience for test support and automation 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.