HR Coordinator

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.  

As an HR Coordinator at Castelion, you’ll play a critical role in keeping our people operations running smoothly while helping build the infrastructure needed for our next stage of growth. You’ll own key processes across the employee lifecycle, including I-9 and E-Verify compliance, benefits administration, onboarding, time and attendance, offboarding, employee support, and HR reporting. You’ll be a trusted resource for employees and a key operational partner to the HR team. This is a hands-on role for someone who is exceptionally organized, detail-oriented, resourceful, and comfortable moving quickly, solving problems, and taking ownership.

What You’ll Do

HR Operations & Employee Support

• Serve as support for employee questions related to HR, payroll, benefits, policies, time and attendance, and other workplace needs.
• Process employee lifecycle changes, including hires, transfers, promotions, manager changes, status changes, and separations.
• Maintain accurate HRIS data and employee records while handling sensitive information with discretion.
• Triage workplace concerns and escalate complex or sensitive matters to the appropriate HR team member.

Compliance & Benefits

• Own I-9 and E-Verify administration, ensuring timely and accurate completion while monitoring and resolving Tentative Nonconfirmations, Cases in Continuance, and other E-Verify cases.
• Conduct routine audits of employee records, required acknowledgements, and compliance documentation.
• Manage Qualifying Life Events (QLEs), monitor Evidence of Insurability (EOI), and support employees with benefits enrollment and eligibility questions.
• Track and drive completion of required employee training, including compliance, safety, and company-mandated training, ensuring deadlines are met and records remain accurate and audit-ready.
• Support Workers’ Compensation claims, including documentation, claim tracking, employee follow-up, and coordination with the Workers’ Compensation carrier.

Onboarding & Offboarding

• Partner with Recruiting to deliver a seamless transition from offer acceptance through onboarding, including pre-employment requirements, HRIS setup, employment documentation, and required acknowledgements.
• Support offboarding coordination, including separation documentation, HRIS transactions, payroll inputs, benefits notifications, and cross-functional workflows.

Time, Attendance & Payroll

• Review hourly employee timesheets in preparation for bi-weekly payroll and support time and attendance compliance.
• Resolve missing punches, timesheet errors, change requests, and outstanding approvals to ensure all worked hours are accurately captured and approved for payment.

HR Reporting & Process Improvement

• Build and maintain HR reports, dashboards, and KPIs, including headcount, turnover, attendance, and other workforce metrics.
• Analyze HR data to identify trends, discrepancies, and opportunities for improvement.
• Create and maintain SOPs, trackers, templates, and employee resources.
• Improve HR processes, tools, and workflows through stronger controls, automation, and scalable solutions.

Basic Qualifications

• Associate’s or Bachelor’s degree in Human Resources, Business, or a related field, or equivalent professional experience.
• 2+ years of HR, People Operations, or related experience.
• Strong organizational skills with exceptional attention to detail and follow-through.
• Excellent written and verbal communication and relationship-building skills.
• Ability to manage competing priorities and operate effectively in a fast-paced environment.
• Strong judgment and discretion when handling confidential information.
• Proficiency with HR systems, spreadsheets, reporting, and employee data.
• Ability to work onsite full-time. This is not a remote or hybrid role.

Preferred Qualifications

• Experience in a high-growth, manufacturing, aerospace, defense, or technology environment.
• Experience supporting hourly and non-exempt employee populations.
• Strong Excel skills, including formulas, XLOOKUP/VLOOKUP, pivot tables, data analysis, and reporting

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 [email protected]. 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.