Principal Test Software Engineer

Please Note: To conform with the United States Government Space Technology Export Regulations, the applicant must be a U.S. citizen, lawful permanent resident of the U.S., conditional resident, asylee or refugee (protected individuals as defined by 8 U.S.C. 1324b(a)(3)), or eligible to obtain the required authorizations from the U.S. Department of State.

At Cesium Astro
, we are developers and pioneers of out-of-the-box communication systems for satellites, UAVs, launch vehicles, and other space and airborne platforms. We take pride in our dynamic and cross-functional work environment, which allows us to learn, develop, and engage across our organization. If you are looking for hands‑on, interactive, and autonomous work, Cesium Astro is the place for you. We are actively seeking passionate, collaborative, energetic, and forward‑thinking individuals to join our team.

We are looking for a Principal Embedded Software Engineer I to design, develop, and maintain automated test systems for embedded hardware and firmware. In this role, you’ll work closely with embedded software, hardware, and systems engineers to ensure our products are reliable, robust, and production‑ready. You’ll own test infrastructure from low‑level hardware validation through system‑level and regression testing.

This role is ideal for someone who enjoys building test frameworks, working close to the hardware, and improving product quality through automation and thoughtful test design.

• Design and implement automated test software for embedded systems.
• Develop test frameworks for unit, integration, hardware‑in‑the‑loop (HIL), and system‑level testing.
• Write test code in C/C++, Python, or other scripting languages to validate firmware and hardware behavior.
• Interface with embedded targets using UART, SPI, I2C, CAN, Ethernet, JTAG, and other protocols.
• Collaborate with firmware and hardware teams to define test requirements and acceptance criteria.
• Debug failures across software, firmware, and hardware layers.
• Integrate tests into CI/CD pipelines and support regression testing.
• Create and maintain test documentation, reports, and metrics.
• Continuously improve test coverage, reliability, and execution time.

• Bachelor’s degree in Computer Engineering, Electrical Engineering, Computer Science, or equivalent experience.
• Minimum of 9 years of experience with embedded systems and low‑level software.
• Proficiency in C/C++ and/or Python.
• Experience developing automated test software, not just manual testing.
• Familiarity with RTOS or bare‑metal systems.
• Experience debugging using oscilloscopes, logic analyzers, or JTAG/debug probes.
• Solid understanding of software testing principles and test automation best practices.

• Experience with HIL/SIL testing or custom test rigs.
• Familiarity with CI systems (Git Hub Actions, Jenkins, Git Lab CI, etc.).
• Experience testing safety‑critical or high‑reliability systems.
• Knowledge of Linux‑based embedded systems.
• Exposure to aerospace, automotive, robotics, or industrial embedded products.

Cesium Astro considers several factors when extending an offer, including but not limited to, the role and associated responsibilities, a candidate’s work experience, education/training, and key skills. Full‑time employment offers include company stock options and a generous benefits package including health, dental, vision, HSA, FSA, life, disability and retirement plans.

Cesium Astro is an Equal Opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, disability, protected Veteran Status, or any other characteristic protected by applicable federal, state, or local law.

Please note:

Cesium Astro does not accept unsolicited resumes from contract agencies or search firms. Any unsolicited resumes submitted to our website or to Cesium Astro team members will be considered property of Cesium Astro, and we will not be obligated to pay any referral fees.