• Assist the Tax Manager with the preparation of supporting workpapers and submission of indirect tax filings for the United States, leveraging internal and external resources • Prepare, review, and maintain sales and use tax account reconciliations and other tax-related month-end close support • Assist with the annual financial statement process, including reconciliations, journal entries, and supporting schedules • Manage and support indirect tax audits, notices, IDRs, and controversy matters, including gathering documentation, performing reconciliations and analysis, coordinating responses, and maintaining audit trackers • Maintain recordkeeping for state sales tax filings, tax notices, audit documentation, and jurisdictional portal activity • Monitor state and local tax legislation for changes relevant to StockX, research the impact, and help drive implementation of necessary changes • Research and analyze domestic indirect tax implications of new business initiatives, and provide recommendations to mitigate tax exposure • Partner cross-functionally with business teams to support implementation of tax requirements for new products, processes, and operational changes • Support tax engine, systems, and process testing, including UAT and issue tracking tied to tax-related changes • Proactively monitor the accuracy of tax charges and system-calculated tax results, identify discrepancies through analysis and reconciliation, and partner with cross-functional teams to investigate root causes and implement solutions • Assist with registrations, annual compliance requirements, special projects, and ad hoc requests from business partners and external advisors

Role Description At Prosci, we help organizations navigate change with confidence. As our global footprint continues to grow, so does the complexity and strategic importance of our finance operations. We are creating a new Principal, Tax role to bring dedicated senior-level ownership, expertise, and leadership to these areas, with tax as the core focus of the role. Reporting into the Director, Corporate Controller, this is a high-impact leadership role with significant visibility across the organization. The person in this role will lead Prosci’s global tax strategy across: - Transfer pricing - Technical tax governance - Uncertain tax positions - Tax planning This is an opportunity to shape policy, influence strategic financial decisions, and help build the foundation for Prosci’s continued global growth. At Prosci, we are a purpose-driven organization full of passionate, curious, and results-oriented people. Working at Prosci means being part of a dynamic team that is dedicated to our purpose of creating a world where change is done right. Key Responsibilities - Tax: Policy, Planning & Technical Oversight - Tax Strategy & Governance: Lead global tax strategy, policy development, and technical governance across all jurisdictions, including compliance visibility and documented policy positions. - Transfer Pricing: Own the global transfer pricing framework, including policy design, intercompany pricing documentation, and defense of intercompany arrangements with tax authorities. - Technical Tax Review: Review significant tax filings and positions across key jurisdictions before filing. - Tax Planning: Drive global tax planning initiatives, including IP structuring, interest deductibility, R&D incentives, treaty utilization, and other optimization opportunities. - Tax Audit Defense: Lead all tax authority interactions and audit defense globally, coordinating with external advisors and keeping the Corporate Controller informed. - Regulatory Monitoring: Monitor global tax and regulatory developments, including Pillar Two, VAT / GST changes, and US tax developments, and advise leadership on enterprise implications. - External Vendor Management: Manage all external tax vendor and advisor relationships, including scope, engagement, fees, and performance, ensuring an appropriately scoped and cost-effective advisor network across all jurisdictions. - Uncertain Tax Positions: Identify, assess, and document uncertain tax positions; maintain the UTP register and ensure appropriate ASC 740 treatment in the financial statements. Qualifications - Bachelor's degree in accounting, finance, or a related field required - CPA required - Advanced degree in tax (MST, LLM in Taxation) preferred but not required - 10–14 years of progressive international tax experience, including meaningful in-house or advisory leadership - Demonstrated hands-on experience leading global tax operations, transfer pricing, and tax audit defense across multiple jurisdictions Requirements - Competencies: - Business Acumen: Connects tax decisions to enterprise financial outcomes, including EBITDA, cash flow, and effective tax rate. - Technical Judgment: Makes defensible calls on uncertain tax positions, transfer pricing methods, and contested technical tax matters. - Action Oriented: Manages critical deadlines and complex deliverables with consistency, accuracy, and strong judgment. - Stakeholder Influence: Partners credibly with the Corporate Controller, Sr. Controllers, lenders, and external counsel. - Organized and Detail Oriented: Maintains disciplined oversight of multi-jurisdiction compliance, governance, and policy requirements that other functions depend on. - Technical/Functional Skills: - International tax: Transfer pricing, cross-border structures, and multi-jurisdiction compliance oversight. - Entity rationalization / M&A integration: Wound down or merged legal entities and understands the sequencing of legal, tax, and accounting steps. - Technical tax writing: Produces defensible uncertain tax position memos and transfer pricing policy documentation. - Accounting fluency: Substantive conversations with the Corporate Controller and Sr. Controllers on how tax positions flow through the financial statements. Benefits - Comprehensive wellness benefits - Generous flexible paid time off - Holidays and volunteer time - Medical, dental, vision, long-term and short-term disability programs - Life insurance - Pet insurance - 401k with company matching - Access to LinkedIn Learning - Vibrant “mostly virtual” culture with opportunities to collaborate - Employee-led interest and resource groups - In-person local or market-wide events

• Lead global tax strategy, policy development and technical governance across all jurisdictions • Own the global transfer pricing framework, including policy design • Review significant tax filings and positions before filing • Drive global tax planning initiatives • Lead all tax authority interactions and audit defense globally • Monitor global tax and regulatory developments and advise leadership • Manage all external tax vendor and advisor relationships • Identify, assess, and document uncertain tax positions

Role Description Turn the tax judgement you exercise every quarter into the benchmark frontier AI is graded on. You've owned provisions, run planning across jurisdictions, and taken positions you had to defend. Now that expertise has a new application: shaping how frontier AI models reason through complex tax problems the way an experienced practitioner does. What You'll Do - Design realistic tax tasks: provision calculations, planning scenarios, and multi-jurisdictional questions without a single clean answer. - Write evaluation rubrics that capture sound tax reasoning, defensible positions, and the trade-offs behind them. - Review AI-generated provisions, computations, and analyses for technical accuracy and compliance. - Build reference solutions across direct and indirect tax that anchor how the research evaluates model output. - Flag where models misapply rules, miss jurisdictional nuance, or take positions that wouldn't survive review. Qualifications - 5–8+ years in tax — public accounting practice or a corporate tax function. - You've owned a provision or run planning across jurisdictions. - CPA, EA, ACA / CTA, or equivalent (preferred, not required). - You can explain a position clearly enough to teach the reasoning, not just the result. Requirements - Fully remote, part-time and flexible. - Work is scoped by project and ranges from short engagements to ongoing collaborations, structured as a contract or a monthly retainer. Compensation - $80–$200 per hour, aligned with expertise, scope, and impact; exceptional or highly specialised expertise can go higher. - Ongoing engagements are typically structured as a monthly retainer rather than hourly billing.