Founding Product Engineer

The role

Location: NY, in-office

We’re hiring a Founding Product Engineer to build UnitedOS alongside our network of accounting firms. We’re starting with a practice management platform for firms working with AI agents (think of it as “vertical agent orchestration platform”), with a broader vision: a financial platform and back office for small and medium-sized businesses.

You will own product engineering end-to-end: from design prototypes to shipping and evaluating impact of features in production. You’ll work directly with founders and customers. You will discover requirements, build prototypes, define the optimal AI application strategy for the target use-cases, and shape the long-term vision of the shipped features, both from product and engineering perspective.

What you will own

• Product projects. Own a product engineering area, such as how accounting teams coordinate work with AI agents, and work directly with customers and founders to turn ambiguous needs into a clear scope, decide what to build first, and evolve the solution as you learn from real usage.
• Implementation of customer-facing features. Build across the frontend, backend and AI to turn product ideas into reliable, polished features. Own the path from early prototype through production rollout, including the details that make a feature useful in users’ daily work.
• Engineering design. Design the architecture, data models, and interfaces behind your features, balancing speed of delivery with reliability and room to evolve. Use engineering judgment to decide where deterministic code, AI workflows, or autonomous agents best serve the problem.
• UI/UX design. Shape user flows and interactions that make complex accounting workflows feel simple, drawing on emerging design patterns from the best products and adapting them thoughtfully to our users’ needs.
• Moving the needle. You ensure that your work meaningfully increases human productivity by reliably automating significant portions of their workload.
• Shaping what comes next. Your observations and hands-on experience with moving the needle will directly influence product development and how the product evolves around an agentic paradigm.

What you will be doing

• Prototype and validate solutions. Build prototypes to test technical feasibility and usability, resolve key unknowns, and align the team on architecture and UX before committing to a final version.
• Stay close to customers. Talk with accounting teams, observe their workflows, and use production data and feedback to identify problems and prioritize next steps within your projects.
• Shape projects with founders and product leads. Explore potential solutions, challenge assumptions, and define a scope that delivers meaningful customer value quickly.
• Turn ambiguous needs into clear requirements. Write concise PRDs that capture the user problem, proposed behavior, key edge cases, and success criteria.
• Build and ship across the stack. Implement frontend and backend features, test critical user flows, and own production rollout and follow-through on bugs, usability, and performance.
• Define how we work with AI. Experiment with AI tools in development, testing, and internal operations, and turn approaches that prove useful into repeatable team practices, building truly AI-native company.
• Turn emerging AI use cases into product experiences. Identify new AI use cases relevant to our product, assess where they could improve our users’ life, and own their path from prototype to production.

What we are looking for

• Founder, founding engineer, engineer <> product manager career switch, or early-stage startup experience is especially valuable.
• High agency, clear communication, and comfort working directly with domain experts.
• Strong curiosity about accounting and fintech. To make a meaningful impact in vertical AI, you will need to learn the details of how accounting work is actually done.
• Generalist mindset: you’re not afraid to handle the month-end close, talk to customers, analyse raw technical data, design features, design software architecture, resolve bug requests, and ship features on your own.
• Strong software engineering or math/physics fundamentals validating engineering judgement.
• A strong eye for design: you love using beautiful products and surrounding yourself with beautiful things. You have little patience for mediocre products. Ideally, you made UI/UX design for multiple features/products before.
• A strong user empathy: you love talking with users and build features for solving real peoples’ problems, rather than flashy features that demo well / excite technical folks but deliver little value to the real world.
• First-principles thinking and the judgment to determine how real work should be distributed among AI agents, AI workflows, and deterministic code.
• Evidence of taking ambiguous problems from initial idea to deployed, measurable outcomes.