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.