The ocean covers 71% of our planet, yet we know less about it than the surface of Mars. Apeiron Labs is on a mission to change that. We’re not just building underwater vehicles - we’re building systems that will reshape weather prediction, revolutionize aquaculture, transform shipping, and strengthen national security. We’re developing breakthrough technologies that slash ocean sensing costs by orders of magnitude.

Join a crew of passionate battle-tested subsea specialists, robotics experts, firmware architects, and full-stack cloud engineers. This is a unique opportunity to play a role in the future of ocean intelligence and contribute to humanity’s understanding of our oceans.

Apeiron means unbounded in Greek. The challenge is unbounded. The opportunity is unbounded. Your creativity can be unbounded too.

We are seeking a hands-on, detail-oriented Controller with a strong FP&A orientation to build and own the company’s financial infrastructure from the ground up. This is a rare opportunity to define how finance operates at a high-growth startup - owning the books, the close, and the controls, while also being the analytical business partner to the CEO and leadership team.

This role is located in Boston, MA and our ideal candidate will work onsite in our office there. Prior experience working for a government contractor governed by the DCAA & FARS is a must.

Responsibilities

• Own the monthly, quarterly, and annual close process, ensuring accurate, timely, and GAAP-compliant financial statements.
• Build and maintain accounting policies, internal controls, and documentation appropriate for an early-stage company preparing to scale.
• Manage the general ledger, revenue recognition, accruals, reconciliations, and chart of accounts.
• Oversee accounts payable, accounts receivable, payroll, and treasury/cash management.
• Lead relationships with external accountants, auditors, tax preparers, and banking partners; manage the annual audit and tax filings.
• Ensure compliance with relevant tax, regulatory, and equity administration requirements (including cap table and option grant support alongside legal/HR).
• Stand up scalable systems and tools (accounting software, ERP, expense management) that will support the company through its next several stages of growth.
• Build and own the company’s financial model, annual budget, and rolling forecasts, including scenario and sensitivity analysis.
• Deliver monthly reporting packages and board materials that translate financial results into clear insight for the CEO, leadership team, and investors.
• Develop and track KPIs and unit economics that matter most to the business, partnering with department leads to set and monitor budgets.
• Manage cash flow forecasting and runway analysis, and support fundraising efforts with financial diligence materials, data rooms, and investor reporting.
• Provide ad hoc financial analysis to support pricing, hiring plans, vendor negotiations, and other strategic decisions.
• Interface with the Defense Contract Audit Agency (DCAA) for annual audits and prepare and deliver monthly billing statements for ongoing DoD contracts.
• Identify opportunities to improve margins, efficiency, and financial visibility as the company scales.
• Serve as a trusted financial advisor to the CEO and leadership team, with a seat at the table for major strategic and operating decisions.

Skills and Requirements

• 8+ years of progressive experience in accounting and/or FP&A, including meaningful experience owning a close process and building financial models.
• Prior experience at a startup or high-growth company strongly preferred; comfort operating with limited infrastructure and building it as you go.
• Strong technical accounting foundation (GAAP); CPA and/or MBA a plus but not required.
• Demonstrated FP&A skill: financial modeling, budgeting, forecasting, and translating numbers into a clear business narrative.
• Track record of managing external partners (auditors, tax advisors, banks) and, ideally, exposure to fundraising or investor reporting.
• Excellent communication skills — able to work directly with a CEO and non-finance stakeholders, and to present financial information clearly to a board.
• High ownership mentality: comfortable being the only finance person in the building, with the judgment to know when to escalate and when to just get it done.
• Proficiency with modern accounting/FP&A tooling (e.g., QuickBooks/NetSuite, spreadsheet-based or purpose-built modeling tools; experience selecting/implementing new systems is a plus).
• Experience scaling a finance function through a Series A/B and beyond, including transitioning from an outsourced or fractional finance setup to an in-house team is a plus.
• Prior experience hiring and managing accounting or FP&A staff a plus
• Familiarity with equity compensation administration and cap table management a plus

Apeiron Labs is an Equal Opportunity Employer. We are committed to fair and equitable compensation for all employees. We thoughtfully consider a wide range of factors when determining individual compensation. The expected annual pay range for this role $175,000 - $200,000.