Senior Product Engineer

Job description

We're building a new system of record for finance, one that understands not just the numbers, but the business context behind them. At its core is our Operational Ledger: a financial data layer that preserves every event, calculation, policy, source, and decision behind the financials, rather than reducing them to contextless entries. Questions that once took weeks to answer become as routine as a Google search: Why did margins change? Which customers are actually profitable? How are we tracking against budget? We're not bolting AI onto legacy software. Quanta was built from the ground up around granular financial data, flexible primitives, and systems that agents can safely understand and act on. We've spent years closing the books for real, fast-growing companies and turning what we learn into product. We've already replaced much of what QuickBooks and NetSuite can do and the manual work surrounding them. Customers are now turning off legacy accounting systems and moving to Quanta. We're still early. The problems are hard, the ambition is enormous, and there's no playbook for what we're building. THE TEAM We're a small tight-knit team working together in person in downtown San Francisco. Our team brings together deep expertise in engineering and finance. We've built accounting systems at Affirm, ledgers at Stripe and Robinhood, launched products from 0→1, scaled infrastructure processing billions of dollars, built finance functions, and closed the books under real operating pressure. We understand our customers because we have been in their shoes. Quanta's earliest product was built around a few principles we still value: get to learning as quickly as possible, find the simplest solution that works, and build alongside real users and real-world edge cases. Quanta is for people who want ownership, prioritize learning and outcomes over conventional playbooks, and are comfortable figuring things out as they go. The principles behind our earliest product still shape how we build today: get to learning fast, choose the simplest solution that works, and build with real users in the messy reality of real-world edge cases. WHAT WE’RE LOOKING FOR - 6–7+ years of full-stack engineering experience, ideally on small, high-impact B2B teams - Strong technical fundamentals across modern backend and frontend systems - Systems thinking, including API design, data modeling, and reliability - Product mindset with good judgment around tradeoffs - Comfort with ambiguity, ownership, and self-direction - Strong collaboration skills Bonus points for experience with financial systems, ledgers, or accounting workflows. You are excited about working in person with a collaborative team in San Francisco. THIS ROLE IS NOT FOR YOU IF… - You prefer clearly defined problems with detailed specs, rather than shaping solutions in ambiguous spaces. - You are uncomfortable working in a complex, judgment-heavy domain where correctness depends on context, not just code. - You optimize for speed by accepting known gaps in reliability. Trust matters deeply in the systems we build. - You are primarily interested in AI as a standalone feature, rather than as part of a larger, constrained system. - You prefer working independently or remotely from domain experts. This team works closely and in person by design. WHAT SUCCESS LOOKS LIKE IN 6–12 MONTHS - You have deep familiarity with Quanta’s core systems and are comfortable working where correctness is most critical. - You have owned and shipped improvements used daily by internal teams and customers. - You have shaped at least one core abstraction that increases flexibility without compromising trust. - You are a go-to collaborator for engineers and accountants, translating real-world finance problems into clear technical approaches. - You have helped define how the team uses AI in practice to increase leverage. - You are contributing to longer-term technical direction for the Operational Ledger. - You feel strong ownership over outcomes, not just code. WHY QUANTA Build a category, not just features. We're not selling a slightly better version of an established tool. We're changing what companies should expect from their financial systems. Join early enough to matter. We're a small team. The things you discover, build, and prove can become part of how Quanta sells for years. Learn directly from exceptional people. You'll work alongside founders, engineers, and finance leaders who have built financial infrastructure and operated finance functions firsthand. Grow with the company. We're looking for someone who wants to master outbound, take on increasing ownership, and help us build the sales organization that comes next. BENEFITS - Competitive early-stage salary - Competitive early-stage equity - Health, dental, and vision insurance - 401(k) - Take-what-you-need paid vacation - Commuter benefits - Wellness stipend - Paid lunches and dinners in the office - All the equipment and tools you need to do your best work