A QA Engineer at Relativity Space plays a pivotal role in redefining how rockets are designed, built, and flown. Unlike traditional aerospace companies that rely on fixed tooling and legacy processes, Relativity Space leverages giant 3D printers, artificial intelligence, and autonomous manufacturing to build the Terran R launch vehicle. In this highly dynamic environment, quality assurance is not a passive inspection step at the end of a production line; it is an active, engineering-driven discipline integrated into every phase of development, from raw material feedstock to engine hot-fire testing.

Your work in this role directly impacts the safety, reliability, and success of missions. Whether you are based at the Long Beach, CA headquarters focusing on factory integration or at the Stennis Space Center in Mississippi focusing on propulsion testing, you will be responsible for designing test architectures, validating complex hardware systems, and writing software to automate data collection. You will collaborate closely with design, manufacturing, and test operations teams to ensure that novel 3D-printed structures and advanced propulsion systems meet flight-readiness standards.

This role requires a unique blend of physical engineering intuition and modern software capability. You will face challenges that have no pre-existing playbook, such as validating the structural integrity of complex, organically shaped 3D-printed metal parts or troubleshooting high-pressure fluid systems on a test stand. To succeed, you must be comfortable operating at the intersection of hardware, software, and fundamental physics.

The questions you will face during the Relativity Space hiring process are designed to test your core engineering intuition, your ability to think on your feet, and your hands-on technical skills. While these questions are representative of what past candidates have experienced, you should focus on understanding the underlying engineering principles rather than memorizing specific answers.

Fluid Dynamics & Thermodynamics

This category evaluates your understanding of how liquids and gases behave under pressure, which is critical for rocket propulsion and test stand operations.

• Choose between fluid mechanics and thermodynamics, and walk through the derivation of a fundamental governing equation on the whiteboard.
• Explain the operating principles of a centrifugal pump and how you would diagnose cavitation during a test run.

To succeed in the Relativity Space interview process, you must shift your mindset away from rote memorization and focus on first-principles thinking. The interviewers are less interested in whether you know a specific formula by heart and more interested in how you structure your thoughts when faced with an unfamiliar, complex problem.

First-Principles Thinking – You must be able to break complex engineering systems down to their most basic physical laws (e.g., conservation of mass, momentum, and energy). When presented with a problem, start with these fundamentals and build your solution upward.

Technical Rigor & Defense – Expect to defend every assertion you make. If you choose a specific sensor, material, or test method, your interviewer will ask "why?" multiple times. Be prepared to back up your decisions with physical equations, data, or clear engineering trade-offs.

Project Ownership – You must demonstrate deep technical intimacy with the projects on your resume. If you list a project, you should know every detail, including the specific instruments used, the software architecture, the failure modes, and your individual contribution.

Adaptability & Ambiguity – Rocket development is fast-paced and unpredictable. You need to show that you can make sound engineering decisions with incomplete data and adapt quickly when test parameters or requirements shift.

The interview process for a QA Engineer at Relativity Space is rigorous, highly technical, and designed to evaluate both your theoretical knowledge and your practical execution capabilities. The entire process typically takes between three to six weeks to complete, depending on the role level and location.

The process begins with an initial recruiter screening call to assess basic qualifications, alignment with the role, and cultural fit. This is followed by a technical screen, which often involves a live coding assessment or a deep dive into fundamental engineering principles. If you pass these initial stages, you will move on to the final interview loop, which includes a formal presentation of your past work and a series of intensive technical panels.

The timeline above outlines the typical progression from your initial application to the final decision. The recruiter screen focuses on your background and high-level fit, while the technical screen introduces live problem-solving. The final loop is a comprehensive evaluation of your technical depth, presentation skills, and ability to collaborate with a multidisciplinary engineering team.

First-Principles Physics & Engineering Fundamentals

This is the most heavily weighted technical area of the interview. You will be asked to choose from core engineering subjects—typically solids, fluids, thermodynamics, or heat transfer—and solve open-ended problems on a whiteboard.

Be ready to go over:

• Governing Equations – Deriving and applying Bernoulli’s equation, the Navier-Stokes equations, the first and second laws of thermodynamics, and Hooke's law.
• Fluid & Thermal Systems – Analyzing fluid flow through orifices, valves, and pipes, as well as understanding phase changes and heat exchanger design.
• Solid Mechanics – Calculating stress, strain, shear flow, and bending moments in structural components under static and dynamic loading.
• Advanced concepts – Two-phase fluid flow, cryogenic heat transfer, structural dynamics, and random vibration analysis.

Example questions or scenarios:

• "Draw a temperature-entropy diagram for a liquid rocket engine cycle and explain where the greatest inefficiencies occur."
• "A 3D-printed propellant line is experiencing high-frequency vibrations. Walk me through how you would model the stress distribution and design a physical test to validate its fatigue life."

Hardware Testing & Instrumentation

This area evaluates your practical, hands-on experience in setting up tests, selecting instrumentation, and ensuring data integrity.

Be ready to go over:

• Sensor Selection – Choosing the right instrument (thermocouples, RTDs, strain gauges, pressure transducers, accelerometers) for specific environmental conditions.
• Data Acquisition (DAQ) – Understanding sampling rates, signal conditioning, filtering, and analog-to-digital conversion.
• Plumbing & Schematic Interpretation – Reading and modifying P&IDs, understanding valve operations (solenoid, pneumatic, manual), and designing fluid test manifolds.
• Advanced concepts – High-speed data acquisition, cryogenic instrumentation challenges, and error propagation analysis.

Example questions or scenarios:

• "We need to measure the transient pressure spike during the ignition of a thruster. What type of pressure transducer would you select, what sampling rate would you configure, and how would you mitigate signal noise?"
• "Walk me through how you would design a test setup to leak-check a complex 3D-printed manifold that has multiple internal cavities."

Software & Scripting

As a QA Engineer, you will write software to automate test sequences, process test data, and build quality dashboards.

Be ready to go over:

• Object-Oriented Programming – Designing clean, reusable, and maintainable code structures in Python or C++.
• Data Structures & Algorithms – Implementing basic data structures (queues, stacks, hashmaps) and understanding their time and space complexity.
• Data Processing – Using libraries like Pandas, NumPy, or MATLAB to process, filter, and visualize large datasets from physical tests.
• Advanced concepts – Writing hardware-in-the-loop (HIL) test scripts, communicating with instruments via VISA/SCPI, and designing simple graphical user interfaces (GUIs) for test operators.

Example questions or scenarios:

• "Write a Python script that reads a stream of temperature data from a serial port, filters out high-frequency noise using a moving average, and triggers an alert if the temperature exceeds a safety threshold."
• "How would you design an object-oriented framework to represent different types of test instruments in a automated test bench?"

Technical Presentation & Project Defense

During the final loop, you will deliver a 30-minute presentation to a panel of engineers detailing a complex technical project you have executed in the past.

Be ready to go over:

• Project Scope & Requirements – Clearly defining the problem, the constraints, and the success criteria of your project.
• Technical Execution – Explaining your design, analysis, testing, or troubleshooting methodology in deep detail.
• Individual Contribution – Making it explicitly clear what you personally designed, built, coded, or analyzed.
• Lessons Learned – Reflecting on what failed, how you resolved unexpected issues, and what you would improve.