Controller

About the Role

We're looking for a Controller to build the financial reporting and accounting functions at RadixArk from the ground up. This is a true 0-to-1 role — you won't be inheriting a close process or a chart of accounts, you'll be designing both. You'll own the full spectrum of accounting operations, financial reporting, and controls infrastructure, while simultaneously standing up the systems and processes that will scale with us through hypergrowth.

You'll report directly to the Head of Finance & Operations and work in close partnership with the founders. This is a rare opportunity to define what financial rigor looks like at RadixArk — and to build it yourself.

We move fast, operate with a sense of urgency, and expect the same from everyone on the team.

What You'll Own

Accounting & Close

• Own the monthly, quarterly, and annual close process end to end — building it to be fast, accurate, and audit-ready
• Manage all general ledger activity including revenue recognition, accruals, prepayments, and equity accounting
• Prepare and review financial statements in accordance with US GAAP
• Design and enforce the chart of accounts, accounting policies, and documentation standards

Controls & Compliance

• Build and maintain a robust internal controls environment — policies, procedures, and audit trails that can withstand investor and board scrutiny
• Coordinate external audits and manage relationships with auditors, tax advisors, and legal counsel
• Own federal and state tax compliance, including R&D credits, sales tax nexus, and international considerations as we grow
• Ensure compliance with all regulatory and reporting requirements relevant to a venture-backed technology company

Systems & Operations

• Select, implement, and own our core financial systems stack (ERP, expense management, billing, etc.)
• Build the reporting and dashboards that give leadership real-time visibility into financial position and burn
• Establish scalable AP/AR processes and vendor management workflows
• Own payroll operations and coordinate with People on compensation and equity accounting

Strategic Finance Support

• Partner with the Head of Finance & Operations on budgeting, forecasting, and board reporting
• Support fundraising and due diligence processes — you will be a key voice in investor conversations
• Provide financial analysis and decision support to the founders and leadership team

Who You Are

• Available for a hybrid schedule with 3 days per week onsite at our Palo Alto office
• 7+ years of progressive accounting experience, with meaningful time at a high-growth tech company or a mix of Big 4 and startup
• CPA required; experience with venture-backed companies and the associated investor reporting expectations is a strong plus
• Deep command of US GAAP, particularly around revenue recognition (ASC 606), equity accounting, and stock-based compensation (ASC 718)
• Hands-on experience selecting and implementing financial systems — you've done the work, not just managed vendors who did it
• Proven track record managing and elevating external accounting partners — you know how to get more out of your auditors, advisors, and outside counsel than a typical client relationship delivers
• Comfortable operating at every level: you'll set strategy and reconcile accounts in the same week
• Scrappy, resourceful, and relentlessly accurate — you hold the bar on financial integrity without slowing the business down
• Low ego, high output — you do what it takes to get the numbers right and the team equipped to move fast
• Experience supporting audits, fundraising due diligence, or board reporting a strong plus
• International accounting exposure (transfer pricing, multi-entity consolidations) a plus as we grow globally

About RadixArk

RadixArk is an infrastructure-first company built by engineers who've shipped production AI systems, created SGLang (20K+ GitHub stars, the fastest open LLM serving engine), and developed Miles (our large-scale RL framework).

We're on a mission to democratize frontier-level AI infrastructure by building world-class open systems for inference and training. Our team has optimized kernels serving billions of tokens daily, designed distributed training systems coordinating 10,000+ GPUs, and contributed to infrastructure that powers leading AI companies and research labs.

We're backed by well-known infrastructure investors and partner with Nvidia, Google, AWS, and frontier AI labs. Join us in building infrastructure that gives real leverage back to the AI community.

Compensation

We offer competitive compensation with meaningful equity, comprehensive benefits, and flexible work arrangements. Compensation depends on location, experience, and level.

Equal Opportunity

RadixArk is an Equal Opportunity Employer and is proud to offer equal employment opportunity to everyone regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, veteran status, and more.