Controller

Role Overview

Mainstay is hiring a Controller to lead our accounting function as we scale. You'll own the monthly close process end-to-end, build and enforce the internal control environment, and serve as the company's primary authority on technical accounting and financial reporting, partnering closely with the Head of Finance on the broader finance strategy.

What You'll Do

• Own the monthly, quarterly, and year-end close process in full, including journal entries, account reconciliations, and consolidations

• Prepare and take final ownership of accurate, timely GAAP financial statements and supporting management reporting packages

• Design, implement, and enforce the internal control environment as Mainstay scales, building the foundation for future audit and compliance requirements

• Set technical accounting policy — researching and documenting positions on revenue recognition, equity, leases, and other complex areas, and serving as the company's point of authority on GAAP matters

• Define and implement scalable finance and accounting data structures across the ERP, internally managed databases, and fragmented product group data assets

• Own the external audit relationship, including PBC schedules, auditor coordination, and final resolution of technical issues

• Partner with the Head of Finance on budgeting, forecasting, and variance analysis

• Partner with Legal and People teams to maintain and manage the cap table

• Build, manage, and mentor the accounting team as it grows, including hiring and development of accounting staff

• Own accounting systems and ERP strategy, driving automation and process improvement as transaction volume increases

• Lead ad hoc projects tied to fundraising, board reporting, and other strategic initiatives

What You'll Bring

• Bachelor's degree in Accounting or Finance; CPA strongly preferred

• 10+ years of progressive accounting experience, including prior experience as a Controller or Assistant Controller

• Strong working knowledge of U.S. GAAP, with demonstrated experience owning a complete close and preparing consolidated financial statements independently

• Advanced Excel skills and experience with a modern ERP/accounting system

• Prior experience managing and developing an accounting team

Nice to Have

• Experience at a high-growth, VC-backed startup, especially one that has scaled its finance function from the ground up

• Experience working with tools such as Ramp, Rippling, Shareworks, and Sage Intacct

• Experience implementing or migrating accounting systems

• Experience managing external audit and tax return processes end-to-end

• Experience presenting financials to a board or investors