Human Resources Manager

Castelion; Torrance (CA); On-site; USD 120,000 - 160,000; Full time

Job summary

A leading company in defense development seeks a hands-on HR Manager to lead HR operations. This role involves hiring, onboarding, compliance, and culture building. The HR Manager will work closely with leadership to align people practices with company growth, ensuring a supportive environment for employees.

Benefits

Stock options

Medical insurance

Vision insurance

Dental insurance

Three weeks paid time off

Qualifications

• 5+ years of HR experience, ideally in a startup.
• Strong knowledge of California labor law.
• Comfortable in an in-person environment.

Responsibilities

• Own and evolve HR operations across Torrance HQ.
• Manage onboarding, offboarding, and employee lifecycle.
• Ensure compliance with labor laws.

Skills

HR Compliance

Employee Relations

Organizational Skills

Detail-oriented

Communication

Job description

This range is provided by Castelion. Your actual pay will be based on your skills and experience — talk with your recruiter to learn more.

Base pay range

$120,000.00/yr - $160,000.00/yr

Additional compensation types

Stock options

Direct message the job poster from Castelion

Scaling an A+ Team | Series A Startup Driving a Critical Mission | Join Our Rapid Growth Journey

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.

HR Manager

We are looking for a resourceful, hands-on HR Manager to serve as the foundational people leader at Castelion. This is a high-impact role for someone excited to wear multiple hats—supporting hiring, onboarding, compliance, employee relations, culture building, and HR infrastructure. You’ll work closely with leadership to ensure our people practices keep pace with our growth and reflect our values of excellence, urgency, and trust. This role is 100% onsite in our Torrance headquarters, embedded in the action alongside engineering and executive teams.

Responsibilities

• Serve as Castelion’s primary HR lead—owning and evolving HR operations across our Torrance HQ and satellite sites
• Manage onboarding, offboarding, benefits administration, and employee lifecycle processes
• Provide employee relations support and guidance to leadership and employees
• Ensure compliance with federal, state, and local labor laws, including CA-specific requirements
• Help define and reinforce our company culture as we scale
• Build scalable HR systems, policies, and programs from scratch
• Lead initiatives related to performance reviews, compensation benchmarking, and employee engagement
• Support internal communications, employee check-ins, and workplace experience

Basic Qualifications

• 5+ years of HR experience, ideally including time at a fast-paced startup or small company
• Confident navigating ambiguity and building from zero—startup DNA is a must
• Strong working knowledge of HR compliance and California labor law
• Highly trustworthy, empathetic, and people-focused
• Detail-oriented, organized, and responsive—you get stuff done
• Comfortable working in an in-person environment and across different sites
• Bonus: experience supporting engineering-heavy or government-adjacent teams

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 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. The 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.

• 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.

Seniority level

• Seniority level

  Mid-Senior level

Employment type

• Employment type

  Full-time

Job function

• Job function

  Human Resources

• Industries

  Defense and Space Manufacturing, Aviation and Aerospace Component Manufacturing, and Manufacturing

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Inferred from the description for this job

Medical insurance

Vision insurance

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