HITL Test Infrastructure Engineer

Why Castelion, Why Now 

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we're building a world-class team to turn bold ideas into real capability. 

This is a rare opportunity to join at an early stage, where you'll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function.  

HITL Test Infrastructure Engineer

As a HITL Test Infrastructure Engineer, you will architect, develop, and own Castelion's Hardware-in-the-Loop (HITL) test infrastructure used to verify embedded software and firmware running on flight-critical hardware. Your systems will enable developers and automated CI/CD pipelines to reserve physical hardware, deploy software and firmware, execute automated tests, and rapidly validate system performance using production-representative hardware.

You'll work across software, firmware, avionics, FPGA, electrical, and systems engineering teams to build scalable, resilient, and highly automated test environments supporting microcontrollers, FPGAs, GPUs, and custom electronics. Your work will significantly improve development velocity and software quality by providing engineers with fast, reliable feedback before hardware reaches the vehicle.

At Castelion, engineers own their systems from concept through production. You'll design infrastructure that is robust, maintainable, intuitive to use, and capable of scaling alongside our rapidly growing engineering organization.

Responsibilities

• Design, develop, and own Castelion's Hardware-in-the-Loop (HITL) test infrastructure for embedded software and firmware verification.
• Build scalable HITL test stations capable of supporting microcontrollers, FPGAs, GPUs, and custom compute hardware with specialized power and interface requirements.
• Develop automated test frameworks that verify software loading, boot sequences, runtime performance, functional behavior, and system requirements.
• Integrate HITL systems into Kubernetes and CI/CD workflows, enabling developers and automated verification pipelines to reserve hardware, flash devices, execute tests, and review results.
• Develop Python-based test software, automation tools, and infrastructure to maximize test coverage and engineering productivity.
• Design automated test execution strategies for code commits, pull requests, nightly builds, release candidates, and other development milestones.
• Build reliable hardware reservation, scheduling, and resource management capabilities that maximize lab utilization.
• Partner closely with software, firmware, FPGA, avionics, electrical, and systems engineers to define verification requirements and expand automated test coverage.
• Debug complex issues spanning hardware, firmware, software, networking, and infrastructure.
• Continuously improve the reliability, scalability, uptime, automation, and user experience of Castelion's HITL infrastructure.
• Support board bring-up, hardware integration, lab automation, and prototype testing activities as new hardware platforms are introduced.
• Establish best practices for automated verification, hardware management, and continuous integration across engineering teams.

Basic Qualifications

• Bachelor's degree in Computer Engineering, Electrical Engineering, Computer Science, Software Engineering, or a related technical discipline, or equivalent practical experience.
• Experience developing software using Python.
• Experience building automated test frameworks using tools such as pytest, Robot Framework, or similar.
• Familiarity with embedded software and firmware development workflows, including flashing, booting, debugging, and runtime validation.
• Experience working with serial, JTAG, SWD, or similar hardware debug interfaces.
• Basic understanding of embedded hardware and the ability to read electrical schematics.
• Experience working in Linux development environments.
• Basic understanding of Kubernetes, containerized infrastructure, or modern CI/CD systems.
• Ability to troubleshoot issues across hardware, firmware, software, and infrastructure boundaries.
• Comfortable working in a laboratory environment with custom electronics, instrumentation, power supplies, and prototype hardware.

Preferred Skills and Experience

• Experience developing Hardware-in-the-Loop (HITL) or automated hardware test systems.
• Experience integrating hardware validation into CI/CD pipelines.
• Experience with microcontrollers, FPGAs, GPUs, SoCs, or custom embedded compute platforms.
• Experience with board bring-up, lab automation, instrument control, power sequencing, or custom power delivery systems.
• Familiarity with FPGA development workflows, including VHDL, Verilog, or SystemVerilog.
• Experience reading FPGA code to understand interfaces, expected behavior, and verification requirements.
• Experience with Git-based software development workflows.
• Experience building hardware reservation, orchestration, or resource scheduling systems.
• Experience with networking, distributed systems, or Kubernetes-based infrastructure.
• Experience developing scalable engineering infrastructure supporting multiple development teams.

Castelion offers a generous benefits package. Please refer to the bottom of our Careers page for more details.  

Other Duties 

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice. 

Additional Eligibility Requirements 

This position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply. 

Affirmative Action/EEO Statement 

Castelion is an Equal Opportunity Employer. We are committed to providing equal employment opportunities to all applicants and employees without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, genetic information, protected veteran status, or any other characteristic protected by applicable federal, state, or local law. 

Castelion is committed to providing reasonable accommodations to qualified individuals with disabilities throughout the application and hiring process. If you require a reasonable accommodation to complete an application, participate in the interview process, or otherwise participate in the hiring process, please contact hr@castelion.com. Requests for accommodation will be considered on an individual basis and handled in accordance with applicable law. 

Castelion is committed to fostering a workplace where employment decisions are based on qualifications, business needs, and the ability to perform the essential functions of the role, with or without reasonable accommodation. 

EAR/ITAR Requirements 

This position requires access to export-controlled information, and as such, employment (or hiring of a contractor) is contingent upon the candidate’s ability to access all applicable export-controlled information without additional export licensing being required by the Bureau of Industry and Security and/or the Directorate of Defense Trade Controls.