Payload Flight Software Engineer

Job description Team & Reporting Line: Imaging Operations team Our Mission At constellr, we're harnessing the power of space to solve one of Earth’s greatest challenges: climate resilience & security in a changing world. Our thermal satellite constellation delivers the most accurate land surface temperature data on the market, equipping commercial players, governments, defence agencies, and global institutions with the thermal intelligence they need to make strategic decisions– from national security and infrastructure to agriculture and climate resilience. As a fast-scaling company with offices in Brussels, Freiburg, Munich, Washington and Toulouse, our multidisciplinary team of engineers, scientists, and strategists is building the future of space-based Earth observation Your Role As part of the constellr Imaging Operations team, you will build, maintain, and operationalize our onboard payload software — carrying the payload from commissioning through to day-to-day in-orbit operations across the satellite's full lifecycle. This is a hands-on, high-impact role focused on turning flight software into reliable, operational reality. You will be involved in the design and contribute operational feedback that helps shape it, you will drive the operationalization of in orbit payload software, supporting operations, anomaly solving and commissioning on each new satellite. You'll collaborate closely across the business — working day-to-day with internal engineering teams, Product Assurance, Project Management, and Operations, as well as external suppliers — and you'll operate at a high interface with the hardware and operations teams, ensuring the software runs reliably on the payload hardware. Your work will directly influence the reliability, performance, and long-term success of constellr's mission, helping turn mission concepts into robust, flight-ready, operational software systems. Key responsibilities Develop, test, and maintain high-reliability onboard payload software, with a focus on making it operational and flight-ready in compliance with product assurance and safety standards. Support the commissioning of the payload and on-orbit activities for each new satellite in the constellation. Support in-orbit operations and the operations team, ensuring the onboard software performs reliably in flight. Provide operational feedback into software requirements and design across onboard satellite systems, collaborating with cross-functional stakeholders. Contribute to the evolution of onboard software architecture, with emphasis on in-orbit operational systems and laboratory-based validation environments. Support the implementation and validation of Fault Detection, Isolation and Recovery (FDIR) strategies to ensure the resilience and autonomy of onboard systems. Work at a high interface with the hardware team to make the software operational on the payload hardware. Support the delivery of new software features and upgrades, working closely with external suppliers and development partners. Support verification and validation activities for onboard systems and flight software, from laboratory testing through to in-orbit performance. Contribute to integration and testing activities using Flatsat environments and other ground-based simulation and validation platforms. Support the investigation and resolution of payload anomalies and non-conformance issues, contributing to continuous improvement and system reliability. Help define and enhance the in-orbit software update process for satellites within the constellation fleet. Champion strong configuration management practices across onboard software components to ensure traceability, integrity, and control. Develop and optimize tools for ground-based and in-flight testing, including automation frameworks, to elevate the reliability and efficiency of satellite command execution. Job requirements About you Required: We're looking for someone with strong engineering fundamentals and real-world experience building software for complex, safety-critical or aerospace systems. Degree in Aerospace Engineering, Software Engineering, Computer Science, or a related field. At least 4 years of experience in software development or software assurance, ideally in aerospace or other safety-critical domains. Experience with embedded software development. Solid grounding in software engineering principles, development methodologies, and lifecycle management tools. Experience with software testing frameworks, tools, and processes. Strong practical experience using Git and working within CI/CD pipelines. Proficiency in Python. Solid understanding of common communication protocols across various layers of the stack (e.g., CCSDS, CSP). Nice to Have : These skills would further strengthen your profile, but are not essential: Experience with satellite commanding systems and procedures. Familiarity with satellite operations, including both onboard and ground-based Fault Detection, Isolation, and Recovery (FDIR) processes. Experience with scripting languages such as Bash and Lua Experience with Java, C, or C++ Why join constellr? High-Impact National Security Mission: Be part of an ambitious mission to launch the world’s first commercial thermal infrared constellation, delivering sovereign-grade "behavioural" intelligence from space to close critical blind spots for defence, intelligence, and maritime surveillance agencies. Fast-Paced "New Space" Innovation: Work at the leading edge of a rapidly evolving defence sector. By leveraging modern, agile New Space methodologies, you will help design, build, and deploy dual-use thermal payloads into operational orbit at a speed and scale that traditional aerospace models simply cannot match. Broad Interdisciplinary Exposure: Accelerate your professional growth by collaborating daily with a diverse, international cohort of astrophysicists, software developers, and defence-system engineers. Inclusive & Scientific Culture: Join a high-trust team deeply committed to diversity, inclusion, and scientific excellence, where academic curiosity is paired with high autonomy and a flat hierarchy. Financial Upside & Well-being: Benefit from a Virtual Share Option Plan (VSOP) for permanent employees, giving you a true stake in the company's growth, alongside highly flexible hybrid working models.