Human Resources Manager

Human Resources Manager

This role is fully onsite in Bloomfield, CT, five days per week. The company will be relocating to Suffield, CT later in 2026.

Liquid Piston is an advanced technology company developing innovative rotary-engine propulsion and power solutions for aerospace, defense, and commercial applications. Our patented technology enables compact, efficient, high-performance systems for next-generation platforms. We operate in a fast-paced environment where technical excellence, practical execution, and continuous improvement matter.

The Opportunity:

We are seeking a hands-on Human Resources Manager to own core HR operations and strengthen the people systems that support our continued growth. This role manages the full employee lifecycle and serves as a trusted partner to leadership, managers, and employees across payroll, benefits, employee relations, performance management, compliance, recruiting support, and HR systems. The successful candidate will be comfortable working independently, solving problems, and building clear, scalable processes in a dynamic technical organization.

• Own day-to-day HR operations across recruiting support, hiring, onboarding, employee changes, offboarding, and personnel records.
• Coordinate compliant offer letters in partnership with hiring managers and the company recruiter.
• Maintain accurate, confidential employee records and keep the Employee Handbook, HR policies, and supporting documentation current.
• Continuously improve HR workflows, controls, and documentation to reduce cost, eliminate recurring errors, and increase efficiency and effectiveness.

• Maintain overall accountability for biweekly payroll, with payroll processing performed by the Front Office and Finance & Accounting team. Review PTO and leave balances, and resolve payroll issues promptly.
• Select and administer medical, dental, vision, disability, and related benefit plans, including renewals, open enrollment, enrollments, changes, and employee inquiries.

• Serve as a trusted resource to employees and managers on policies, workplace practices, employee relations, and day-to-day HR questions.
• Lead quarterly and annual performance-review cycles and support performance plans, employee development, training, and manager follow-through.
• Develop initiatives that strengthen engagement, retention, morale, accountability, teamwork, and the overall employee experience.

• Maintain compliance with federal, state, and local employment requirements, including offer letters, notices, workplace postings, leave administration, audits, and remote-employee registrations.
• Coordinate employment visas and complex legal or compliance matters with external counsel and professional advisors as needed.
• Maintain co-op and internship relationships with partner universities and support related early-career programs.
• Manage related HR and administrative projects, including employee expense-report coordination, to ensure smooth and reliable HR operations.

• Five or more years of progressive HR experience, including hands-on ownership of core HR operations.
• Practical experience with payroll, benefits administration, employee relations, performance management, recruiting support, and HR compliance.
• Strong working knowledge of federal and state employment laws, HR documentation requirements, and sound HR practices.
• Experience improving HR processes and administering HRIS, payroll, or timekeeping systems.
• Excellent organization, judgment, discretion, attention to detail, communication, and interpersonal skills.
• Ability to work independently, prioritize competing demands, and take ownership in a growing organization.

• Bachelor's degree in Human Resources, Business Administration, or a related field.
• Experience in a startup, technology, engineering, manufacturing, R&D, or other fast-paced technical environment.
• Experience building scalable HR infrastructure or supporting employees across multiple functions or locations.
• Experience with internship, co-op,…