Founding Product Engineer

ABOUT THE ROLE An early-stage AI-native B2B SaaS company building an AI-driven pricing and monetization platform is looking for a Founding Product Engineer to join as one of the first engineers on the team. This is a hands-on, high-ownership role where you will define architecture, own entire product modules end-to-end, and work directly with customers and leadership to shape how the product evolves. The platform helps B2B companies continuously optimize their pricing lifecycle — covering packaging design, scenario simulation, quote recommendations, deal coaching, discount governance, and more. You will be instrumental in moving core financial logic server-side, extending a typed pricing ontology, and ensuring every feature can be driven by LLM agents. This role is on-site in San Francisco, CA. US work authorization is required; visa sponsorship is not available. WHAT YOU'LL DO - Own whole product modules end-to-end: scope with customers, design versioned APIs, build the UI, ship, and iterate. - Design and evolve architecture for agentic AI systems across Slack bots, terminal UIs, web interfaces, and vendor integrations. - Ensure product features are drivable by LLM agents via MCP/FastMCP server endpoints and conversational interfaces. - Move pricing and business logic off the client into backend services to preserve financial fidelity. - Extend and maintain a typed pricing ontology using Pydantic models (e.g., SKU, Proposition, Persona, Pricing — with Customer, Contract, and Quote on the roadmap). - Lead technical discussions and architectural reviews to keep systems robust, extensible, and secure. - Establish testing, observability, deployment, and performance monitoring practices for AI-driven features. - Mentor peers, influence product strategy, and help set engineering culture and best practices. - Treat money-handling code as load-bearing; prioritize root-cause analysis for production issues. - Adopt and continuously improve an AI-native SDLC where agents assist with code generation and automated review gates. WHAT WE'RE LOOKING FOR Must-haves: - 8+ years of software engineering experience, with demonstrated ownership of full product areas at startup or staff-level scope. - Deep backend expertise with production experience in FastAPI, Python, and MongoDB (or a comparable modern stack). - Proven track record of shipping end-to-end modules: customer scoping → versioned API design → React UI → production delivery. - Credible frontend range with React and TypeScript; able to ship a clean, polished UI independently. - Experience designing server-side business logic, versioned APIs, and ensuring testing, observability, and deployment for AI-driven features. - Experience building or integrating AI-assisted features and agent-driven workflows (e.g., LLM-driven interfaces, MCP-like endpoints). - Familiarity with B2B SaaS monetization concepts: pricing models, packaging, and quoting. - High standards for correctness, especially around financial logic. - Authorized to work in the United States without visa sponsorship. Nice-to-haves: - Experience building MCP servers or tooling for LLM agents. - Background in billing, CPQ, metering, or pricing systems. - Experience with data-dense frontend components and/or conversational interfaces. - Familiarity with data residency, SOC 2, or GDPR-compliant development practices. - Prior experience as a technical founder, co-founder, or early employee who shipped a 0-to-1 B2B product to paying customers. COMPENSATION & BENEFITS - Salary: $200,000 – $250,000 USD per year - Early-stage equity commensurate with a founding-team role - Opportunity to shape product, engineering culture, and company direction from day one LOCATION This is an on-site role based in San Francisco, CA. Candidates must be willing and able to work in person. US work authorization is required; the company does not offer visa sponsorship.