We are seeking a knowledgeable and detail-oriented Senior Payroll Specialist with strong experience in U.S. and international payroll processing, Workday Payroll, and complex tax compliance. This role is critical to ensure accurate and timely payroll execution across multiple countries, with a strong focus on tax filings, audits, and global statutory compliance. The ideal candidate will demonstrate the ability to thrive in both large-scale and fast-growing startup environments, showing adaptability, ownership of end-to-end processes, and hands-on problem solving. Experience with OneSource Virtual (OSV) or a comparable third-party tax provider is strongly preferred.