Stillwater Sciences is looking for an experienced Senior Payroll Specialist to join our Financial Accounting team. In this role, you'll lead accurate, timely, and compliant multi-state payroll processing for approximately 150 employees across seven states while supporting payroll taxes, reconciliations, reporting, and internal controls. If you bring deep payroll expertise, strong attention to detail, and a commitment to operational excellence, please apply! This is a full-time, exempt, 40 hours/week position based out of our Berkeley or Sacramento office, with a preference for Berkeley. What You'll Do Own full-cycle, multi-state payroll processing for exempt and non-exempt employees. Ensure payroll accuracy, compliance, and timely tax filings across jurisdictions. Reconcile payroll-related accounts, deductions, and benefits information. Support audits, reporting, and month-end and year-end payroll activities. Help strengthen payroll systems, documentation, and internal processes. Wh...