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.