Founding Product Engineer

About the Role This is a founding-level, hands-on engineering role at an early-stage B2B SaaS company building an AI-driven pricing and monetization platform. You will own entire product modules end-to-end, work directly with customers and leadership, and help shape both the architecture and engineering culture of a small, fast-moving team. Financial precision and technical leadership are central to this role. What You'll Do Scope, design, build, and iterate on whole product modules independently, from customer conversations through to shipped features. Design and evolve architecture for agentic AI systems across web, conversational, and vendor integration surfaces. Ensure product features are drivable by LLM agents via MCP-style servers and conversational interfaces. Move pricing and business logic off the client and into backend services to preserve financial fidelity. Extend and maintain a typed pricing ontology using Pydantic models covering entities such as SKU, Proposition, Persona, and Pricing. Lead architectural reviews and technical discussions 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 and prioritize thorough root-cause analysis for production issues. Adopt and improve an AI-native development workflow where agents assist with code and automated review gates. What We're Looking For 8 or more years of software engineering experience with proven ownership of product areas at startup or staff-level scope. Strong full-stack skills: deep backend expertise with FastAPI, Python, and MongoDB (or a comparable stack), plus credible React and TypeScript frontend range. Track record of taking ambiguous customer problems to shipped features without a dedicated PM. Experience building or integrating AI-assisted features and agent-driven workflows, including LLM-driven interfaces or MCP-style endpoints. Familiarity with B2B SaaS monetization concepts: pricing models, packaging, quoting, billing, or CPQ. High standards for correctness, especially in financial logic and money-handling code. Ability to design and ship versioned APIs and typed data models. Experience building MCP servers or tooling for LLM agents is a plus. Familiarity with billing, metering, or CPQ systems is a plus. Experience with data-dense frontend components or conversational interfaces is a plus. Prior experience as an early employee or technical founder shipping a 0-to-1 B2B product is a plus. Must be authorized to work in the United States; no visa sponsorship is available. Compensation & Benefits Salary range: $200,000 to $250,000 USD annually. Equity is expected given the founding-level scope. Visa sponsorship is not available. Location On-site in San Francisco, CA. Candidates must be based there or willing and able to relocate.