Mechanical Engineer

Castelion; Torrance (CA); On-site; USD 90,000 - 130,000; Full time

Job summary

Castelion is seeking a hands-on Mechanical Engineer to own the design, fabrication, and integration of critical flight structures for hypersonic vehicles. You will contribute to CAD models, run basic analysis, and work with technicians to bring hardware from concept to flight in weeks, not years.

This role requires a Bachelor’s in Mechanical Engineering and 2+ years in aerospace or hardware-focused industries.

Qualifications

• Bachelor's degree in Mechanical Engineering with 2+ years of professional ME experience, preferably in aerospace, automotive, or hardware-focused industries.
• CAD design of mechanical components (e.g., SolidWorks, NX, or similar); understanding of statics, dynamics, and thermal principles
• Ownership Mentality: Eager to take on responsibility, contribute in a hands-on environment, and learn from experience
• Attention to Detail: Thoughtful about part numbers, materials, tolerances, and documentation-even when moving quickly

Responsibilities

• Design and Develop Flight Hardware: Support the design, analysis, and build of mission-critical systems including composite tanks, separation mechanisms, and actuators. You'll contribute to CAD models, run basic analysis, and work with technicians and leads to integrate and test hardware.
• Rapid Iteration and Prototyping: Contribute to four-week subsystem prototype cycles. Participate in design reviews, integrate test feedback, and help drive continuous improvement based on real-world data.
• Get Hands-On and Learn Fast: Work closely with leads and technicians during builds. Learn how to write travelers, build notes, and quality documentation. Gain exposure to the full product lifecycle in a highly accelerated environment.

Skills

CAD design

Statics & dynamics

Thermal principles

Ownership mentality

Attention to detail

Education

Bachelor's degree in Mechanical Engineering

Tools

SolidWorks

NX

Job description

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.

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.

Mechanical Engineer

Castelion is seeking a hands-on, high-agency Mechanical Engineer excited to take ownership of real flight hardware and grow alongside a fast-moving team. You will work on the design, fabrication, and integration of critical flight structures and mechanisms across Castelion's hypersonic vehicles. This role is ideal for someone who thrives in fast-paced environments, learns quickly, and wants to see their work go from concept to flight in weeks-not years. You'll be empowered to take on meaningful responsibilities immediately. This is a rare opportunity to grow as a full-stack engineer while working on hardware that matters.

Responsibilities

• Design and Develop Flight Hardware: Support the design, analysis, and build of mission-critical systems including composite tanks, separation mechanisms, and actuators. You'll contribute to CAD models, run basic analysis, and work with technicians and leads to integrate and test hardware.


• Rapid Iteration and Prototyping: Contribute to four-week subsystem prototype cycles. Participate in design reviews, integrate test feedback, and help drive continuous improvement based on real-world data.


• Get Hands-On and Learn Fast: Work closely with leads and technicians during builds. Learn how to write travelers, build notes, and quality documentation. Gain exposure to the full product lifecycle in a highly accelerated environment.

Basic Qualifications

• Educational Background: Bachelors degree in Mechanical Engineering with 2+ years of professional ME experience, preferably in aerospace, automotive, or hardware-focused industries.


• Technical Skills: CAD design of mechanical components (e.g., SolidWorks, NX, or similar); understanding of statics, dynamics, and thermal principles


• Ownership Mentality: Eager to take on responsibility, contribute in a hands-on environment, and learn from experience


• Attention to Detail: Thoughtful about part numbers, materials, tolerances, and documentation-even when moving quickly

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 [e-mail]. 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.