Controller

Co-Source Solutions; New York (NY); On-site; USD 180,000 - 260,000; Full time

Job summary

Co-Source Solutions, a NYC-based AI-native software development firm, seeks its first Controller to build the financial infrastructure from the ground up. You will migrate to a multi-entity ERP, establish ASC 606 revenue recognition, and bring accounting in-house to support rapid domestic and international growth.

You'll partner with founders and the CFO, oversee tax across states and Canada, implement Avalara, and drive internal controls and month-end close in a fast-paced startup environment.

Qualifications

• Active CPA with 8+ years accounting experience, starting in public accounting and including 3+ years as Controller or Assistant Controller.
• Experience implementing ERP systems end-to-end, ideally NetSuite, with multi-entity workflows.
• Deep knowledge of sales/use tax, international compliance, and tax automation tools.
• Ability to build internal controls and prepare GAAP financial statements and audits.

Responsibilities

• Architect end-to-end finance infrastructure and lead ERP migration from QuickBooks to NetSuite.
• Partner with product/engineering to design billing, tax, and compliance workflows.
• Manage multi-state nexus, Avalara implementation, and international tax compliance.
• Transition month-end close, AP/AR, 1099s, and internal reporting to in-house team.
• Own GAAP reporting, ASC 606 revenue recognition, and audit readiness for board and partners.

Skills

CPA certification

Public accounting background

Controller or Assistant Controller

ERP implementation

AP/AR management

Taxability & compliance

Education

CPA certification or equivalent

Tools

NetSuite ERP

Avalara tax automation

Job description

We are partnering with a rapidly growing, NYC-based AI-native software development firm to hire its first Controller. Reporting to the CFO and working closely with the founders and engineering team, you will architect the company’s financial infrastructure from the ground up. You will lead the migration to an enterprise ERP, stand up multi-jurisdictional tax compliance, and bring accounting operations in-house to support rapid domestic and international growth.

Key Responsibilities

• Financial Systems & ERP Implementation: Architect end-to-end order-to-cash and procure-to-pay workflows across our platform, payments, and banking stack. Lead the migration from QuickBooks to a multi-entity, multi-currency ERP (NetSuite preferred) and project-based billing system.
• Product & Engineering Partnership: Serve as the internal accounting authority alongside engineers to design APIs, data models, and platform features governing billing, payouts, tax, and compliance.
• Tax & International Compliance: Execute multi-state nexus analysis, registrations, and Avalara implementation. Manage sales and use tax for marketplace transactions, alongside Canadian GST/HST and provincial tax compliance for upcoming expansion.
• Accounting Operations & Insourcing: Transition month-end close and reporting from an outsourced partner to an internal function. Oversee AP/AR, 1099 compliance, reconciliations, and manage a Staff Accountant.
• GAAP Reporting & Audit Readiness: Own the month-end close, GAAP financial statements, and ASC 606 revenue recognition (principal vs. agent). Establish internal controls ahead of the firm’s first financial statement audit and prepare reporting for the board, treasury, and banking partners.

Qualifications

• Experience & Credentials: Active CPA with 8+ years of accounting experience, beginning in public accounting (Big 4 or national firm preferred) and including 3+ years as a Controller or Assistant Controller.
• Systems & Technical Acumen: Proven track record leading an end-to-end ERP and billing implementation (NetSuite strongly preferred). Hands-on experience integrating operational platforms with the general ledger via APIs and data models.
• Specialized Tax & Industry Knowledge: Deep expertise in multi-state sales and use tax, Avalara, and marketplace or two-sided payment flows. Multi-entity, multi-currency, and Canadian indirect tax experience is a strong plus.
• Startup Mindset: Comfortable operating in a high-growth, early-stage environment where you will both build scalable processes and execute day-to-day operations.