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.

Senior Structural Analysis Engineer

We're looking for a Senior Structural Analysis Engineer to help design and validate next-generation hypersonic defense systems. You'll work in a fast-moving startup environment where analysis directly informs design decisions, hardware builds, and flight readiness. This role offers high ownership, close collaboration with design and test teams, and the opportunity to see your work rapidly turn into flying hardware.

Responsibilities

• Build global structural models to evaluate vehicle performance and to provide subsystem loads inputs
• Perform complex, non-linear structural analyses
• Create system level dynamics models to support platform integration
• Develop analysis workflows and methods to accelerate vehicle development
• Define analysis best practices and mentor junior engineers

Basic Qualifications

• Bachelors degree in Aerospace Engineering, Mechanical Engineering, or a related field.
• Strong understanding of structural analysis, structural dynamics, and aerospace materials.
• Experience with FEA tools such as Abaqus, NASTRAN, or similar solvers.
• Comfortable working in ambiguous, rapidly evolving technical environments.

Preferred Skills and Experience

• Masters degree in Aerospace or Mechanical Engineering.
• Experience with launch vehicles, spacecraft, aircraft, UAVs, or propulsion systems.
• Knowledge of fatigue, fracture mechanics, buckling, or thermal-structural analysis.
• Familiarity with aerospace standards and certification processes (e.g., FAA, NASA, MIL).
• Scripting or programming experience (Python, MATLAB) to automate analysis workflows.
• Experience supporting hardware testing or flight operations.

All employees are granted long-term stock incentives as part of their employment at Castelion. All employees receive access to comprehensive medical, vision, and dental insurance, and the company offers four 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.