Founding Product Engineer

About the Role

This is a founding product engineering role at an early-stage B2B SaaS startup building an AI-driven pricing and monetization platform. You will own entire product modules end-to-end, working directly with customers and leadership to shape architecture, ship production-quality systems, and ensure every feature is operable by LLM agents. On a small team, your technical and product judgment will directly define what gets built and how.

What You'll Do

• Scope, design, build, and iterate on whole product modules, from versioned API to React UI, in direct collaboration with customers.
• Design and evolve architecture for agentic AI systems across conversational interfaces, web, and vendor integrations.
• Ensure features are drivable by LLM agents via MCP/FastMCP servers 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 covering SKUs, propositions, personas, pricing, and more.
• 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, shape engineering culture, and contribute to product strategy.
• Treat money-handling code as load-bearing infrastructure, with rigorous root-cause analysis for production issues.
• Adopt and improve an AI-native software development lifecycle where agents assist with code and automated review gates.

What We're Looking For

• 8 or more years of software engineering experience, with demonstrated ownership of entire product areas at startup or staff-level scope.
• Deep backend expertise with production experience in FastAPI, Python, and MongoDB or a comparable stack.
• Credible full-stack skills: able to ship a clean, data-dense React and TypeScript UI independently.
• Track record of taking ambiguous customer problems to shipped features without a dedicated product manager.
• Experience with B2B SaaS monetization concepts: pricing models, packaging, quoting, billing, or CPQ.
• Experience building or integrating AI-assisted features and agent-driven workflows, including LLM interfaces and MCP-style endpoints.
• High standards for correctness, especially around financial logic and money-handling code.
• Familiarity with data residency, SOC 2, or GDPR constraints is a plus.
• Prior experience as a technical founder, co-founder, or early employee who shipped a 0-to-1 B2B product to paying customers is a plus.
• US work authorization required; visa sponsorship is not available.

Compensation & Benefits

The base salary range is $200,000 to $250,000 USD annually. Visa sponsorship is not available.

Location

This role is fully on-site in San Francisco, CA. Candidates must be based in San Francisco or willing to relocate.