Payroll Project Manager & Administrator (Contract)

ON.energy; Miami (FL); Hybrid; USD 90,000 - 120,000; Part time

Benefits offered by this job

Medical insurance

Dental insurance

Vision insurance

401(k) with company match

Paid time off

Company holidays

Job summary

ON.energy seeks a skilled Payroll Project Manager & Administrator on a contract basis to oversee payroll-related projects and daily payroll administration. You will lead system implementations, ensure accurate processing, and maintain compliant payroll practices across US and international sites.

The role requires 5+ years in payroll with 2+ years on projects; CPP or PMP is a plus. Remote or hybrid options may be available depending on project needs.

Qualifications

• Minimum 5 years of experience in payroll administration, with at least 2 years managing payroll projects.
• Proficiency with major payroll platform; Paychex & ADP preferred.
• Proven ability to manage multiple workstreams, meet deadlines, and communicate effectively across all levels of an organization.
• CPP or PMP certification is a plus.

Responsibilities

• Lead payroll system implementations, migrations, or upgrades from planning through go-live, managing timelines, budgets, and stakeholder communication.
• Oversee end-to-end payroll processing, including calculating wages, deductions, bonuses, and tax withholdings.
• Develop and document payroll processes, controls, and standard operating procedures.
• Identify and resolve payroll discrepancies, conducting root-cause analysis to prevent recurrence.
• Manage relationships with external payroll vendors and benefits providers.
• Prepare payroll reports, reconciliations, and audit documentation as needed.

Skills

Payroll administration

Project management

Vendor management

Communication

Education

CPP certification

PMP certification

Tools

Paychex

ADP

Job description

ON.energy is building the power infrastructure that makes the AI era possible. As AI demand surges past what the grid and traditional data centers can support, ON.energy provides a new class of power technology proven at gigawatt scale and trusted by the world’s leading cloud and AI companies. Our systems are already deployed across 2.5 GW of hyper‑scale campuses, validated by top U.S. national labs, and certified for grid‑safe operation by major utilities. With real products in the field, we’re scaling faster than the grid can, transforming power from a bottleneck into a competitive advantage for the companies building the future.

Payroll Project Manager & Administrator (Contract)

We are seeking an experienced Payroll Project Manager & Administrator on a contract basis to oversee and execute payroll‑related projects while managing day‑to‑day payroll administration. This role combines strategic project leadership with hands‑on payroll processing to ensure accurate, compliant, and timely payroll delivery.

Key Responsibilities

Lead payroll system implementations, migrations, or upgrades from planning through go‑live, managing timelines, budgets, and stakeholder communication. Oversee end‑to‑end payroll processing, including calculating wages, deductions, bonuses, and tax withholdings. Develop and document payroll processes, controls, and standard operating procedures. Identify and resolve payroll discrepancies, conducting root‑cause analysis to prevent recurrence. Manage relationships with external payroll vendors and benefits providers. Prepare payroll reports, reconciliations, and audit documentation as needed.

Qualifications

Minimum 5 years of experience in payroll administration, with at least 2 years managing payroll projects. Proficiency with major payroll platform; ideally Paychex & ADP. Proven ability to manage multiple workstreams, meet deadlines, and communicate effectively across all levels of an organization. CPP (Certified Payroll Professional) or PMP certification is a plus.

This is a contract engagement with a defined scope and timeline, to be discussed during the hiring process. Remote or hybrid arrangements may be available depending on project requirements.

For US-based roles - What you’ll get:

• Competitive salary + annual performance‑based bonus eligibility
• Medical, dental, and vision insurance
• 401(k) with company match
• Paid time off and company holidays

For Mexico-based roles - What you’ll get:

• Competitive salary + annual performance bonus eligibility
• Major medical expenses and life insurance
• Paid time off and holidays (per local policy)

For all roles:

• Professional development and growth opportunities
• Opportunity to grow with a mission‑driven team shaping the future of clean energy
• Equal Opportunity: ON.energy is committed to equal employment opportunity and to maintaining a work environment free of harassment, discrimination, or retaliation.
• Accommodations: If you need an accommodation during the application process, email [e-mail]
• Benefits vary by role and location and are subject to change.