Software Infrastructure Engineer

About Castelion

Castelion is bringing a new approach to defense development and production: one that focuses on short, iterative design cycles, rapid testing in development, and modern commercial manufacturing strategies for production at scale. We’re designing, building, and testing next generation long range strike weapons systems to give America and its Allies a definitive edge and deter future conflicts.

Software Infrastructure Engineer

We’re looking for a Software Infrastructure Engineer to design and build the software backbone of our internal test, development, and manufacturing systems. In this role, you’ll create intuitive interfaces and powerful backend systems that allow hardware, software, and test teams to move quickly and stay tightly aligned. You’ll develop tools that interface with hardware-in-the-loop (HITL) stands, enable real-time telemetry monitoring, automate test infrastructure, and streamline data access across the company.

This is a high-impact role for someone who loves to work across the full stack—building everything from web dashboards to CI/CD pipelines—while staying close to the real-world systems they support.

Responsibilities

Build modern web interfaces and internal tools to support engineering, test, and production workflows.

Develop and maintain backend services and APIs for HITL control, data logging, and test coordination.

Create real-time dashboards and telemetry monitoring systems for test and flight operations.

Manage infrastructure for CI/CD, containerization, and automated test pipelines.

Own internal data infrastructure: storage, retrieval, analytics, and visualization.

Collaborate closely with avionics, software, and hardware teams to integrate and scale tools across development phases.

Basic Qualifications

Bachelor's degree in Computer Science, Engineering, or a related technical field

Strong full-stack development skills with experience in modern web frameworks (e.g., React, Vue, Svelte).

Solid backend engineering experience in Python, Go, or Node.js, with well-designed APIs (REST/gRPC).

Comfortable working in Linux environments, with experience in scripting, automation, and system integration.

Familiarity with Docker and CI/CD tooling (e.g., GitHub Actions, Jenkins, etc.).

Experience with databases (PostgreSQL, TimescaleDB, InfluxDB, etc.) and telemetry/metrics systems (e.g., Grafana, Prometheus).

A practical, hands-on mindset and comfort working close to hardware test systems.

Bonus Points

Experience integrating with HITL systems or embedded hardware.

Familiarity with real-time data pipelines, telemetry processing, or lab automation tools.

Exposure to aerospace, defense, or other high-reliability systems.

Passion for building infrastructure that supports tight feedback loops and rapid iteration.

All employees are granted long-term stock incentives as part of their employment as Castelion. All employees receive access to comprehensive medial, vision, and dental insurance, and the company offers three weeks of paid time off per year.

Leadership Qualities

Bias to Action and Creative Problem Solving. Desire and experience questioning assumptions in ways that lead to break through ideas that are ultimately implemented. Successfully bring in applicable processes/concepts/materials from other industries to achieve efficiency gains. Ability to personally resolve minor issues in development without requiring significant support.

High Commitment, High Initiative. A successful candidate will have a genuine passion for Castelion’s mission and consistently look for ways to contribute to the company’s technical goals and prevent hardware blockers. Ability to work in a fast paced, autonomously driven, and demanding atmosphere. Strong sense of accountability and integrity.

Clear Communicator. Proactively communicates blockers. Trusted in previous roles to be voice of company with regulators, suppliers, gate keepers and customers. Capable of tactfully managing relationships with stakeholders to achieve company-desired outcomes without compromising relationships. Emails, IMs and verbal interactions are logical, drive clarity, and detailed enough to eliminate ambiguity.

ITAR Requirements:

• To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.