Software Developer

About Caliburn

Caliburn is an independent company that was spun out of Fathom5 and is focused on building advanced software for tactical and robotic autonomous systems. This position is being posted through Fathom5’s recruiting platform on Caliburn’s behalf, but the role itself is with Caliburn.

Caliburn develops TempestOS, a security-focused operating system built for autonomous and tactical systems operating in demanding environments. The team works across software, edge computing, cybersecurity, robotics, and systems integration to build technology designed for environments where reliability and resilience are critical.

TempestOS is the operating system Caliburn builds for tactical and robotic autonomous systems: robust cybersecurity, edge AI hosting, and services on a Linux kernel. It runs on hardware we do not own, in environments we cannot reach, for customers who cannot tolerate it failing. Code we ship is code no one can reach to fix.

The Caliburn Tempest Software Developer is accountable for implementing and maintaining features in TempestOS services, and for the tests and documentation that go with them. The Tempest Software Developer has three key responsibilities:

1. Implement and integrate features in TempestOS services.
2. • Implement features and fixes from designs and tickets with guidance from senior engineers.
   • Integrate new capabilities into existing OS microservices such as messaging, configuration, and telemetry without breaking current behavior.
3. Deliver code that is tested, documented, and reliable.
4. • Write unit and integration tests and basic documentation for the services and APIs you touch.
   • Monitor, debug, and improve the reliability of TempestOS in development and test environments.
5. Participate in the engineering process.
6. • Take part in code reviews, stand ups, and planning to help refine requirements, edge cases, and tradeoffs.
   • Raise questions early when requirements, assumptions, or edge cases are unclear.

This is a junior individual contributor role with no direct reports. Work is assigned and reviewed by senior engineers, and scope grows as you demonstrate you can own it without supervision.

Implementation and Integration

• Follow the interface, versioning, and documentation standards that keep TempestOS services compatible as they change.
• Flag where a design does not survive contact with the code, early so the correction is cheap.
• Deliver small, well-scoped tasks predictably and with minimal rework.
• Work in the AI Native wayour engineering team uses. Caliburn employs AI agents in the design and development of code with developers providing context and oversight.

Code Quality and Testing

• Produce readable, maintainable code with tests that catch common failure modes.
• Write documentation another developer can work from without coming to find you.
• Extend test coverage when a bug found in development points at a gap.

Reliability and Debugging

• Reduce operational friction by fixing bugs, addressing small reliability issues, and simplifying code paths.
• Reproduce a failure before fixing it, and confirm the fix with a test.
• Work the development and test environments in AWS, including build pipelines, logging, and deployments, well enough to diagnose your own failures.

Team Process and Growth

• Review peers' code as well as receiving review, and act on the reasoning behind a correction.
• Build a working understanding of TempestOS architecture beyond the components you are assigned, so the scope you can own grows.
• Present your own work at internal technical sessions and company demo days when that is the clearest way to share what you learned.

Core

• Zero to two years of professional software engineering experience, including internships and substantial project work.
• Bachelor's degree in computer science, computer engineering, or a related field, or equivalent practical experience.
• Proficiency in at least one modern programming language used for systems or backend development (Go, Rust, C, C++, or Python). Go experience is an advantage.
• Comfort working in a Linux environment: shell, basic tooling, and debugging workflows.
• Basic understanding of distributed systems concepts: services, APIs, message passing, and data serialization.
• Familiarity with Git and common workflows including branching, pull requests, and code review.
• Familiar with AI development and coding tools and comfortable with AI Native development.
• Willingness to learn AWS-based development tooling for build pipelines, logging, and deployments.
• Clear written communication for tickets, code comments, and design clarifications.
• US citizenship, required for clearance eligibility and customer site access.
• Active US Department of War Secret clearance, or the ability to obtain and maintain one over the duration of employment.

Preferred

• Exposure to robotics, autonomous systems, or real-time control software.
• Experience with Protocol Buffers, gRPC, or similar RPC and serialization technologies.
• Understanding of observability basics including logs, metrics, and traces, and how to instrument code.
• Familiarity with AWS developer tooling such as CodeBuild or CodePipeline.
• Kubernetes experience.
• Familiarity with Agile and DevSecOps principles.
• Prior Navy, Marine Corps, or Joint service experience, particularly in engineering, cyber, or unmanned systems roles.

Cultural

• Honest about reality. Brings problems to the team rather than softening them.
• Defaults to verification. Treats LLM output as a powerful but unreliable collaborator, and tests it the same way as any other code path.
• Team-First Mentality. The ability and desire to work in a team environment.
• Startup stamina. Caliburn is building at the intersection of tactical systems and advanced software. That occasionally means long hours, in-person work, and travel.