Founding Product Engineer

About the role

This is a founding-team engineering role at an early-stage AI-driven pricing and monetization platform for B2B SaaS companies. You'll own entire product modules end-to-end — from scoping with customers through architecture, implementation, and iteration — working directly alongside product and leadership on a small, high-trust team where your decisions shape the product and engineering culture.

Responsibilities

• 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 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 (e.g., Pydantic models for SKU, Proposition, Persona, 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, influence product strategy, and set engineering best practices.
• Treat money-handling code as load-bearing infrastructure and prioritize root-cause analysis for production issues.

Requirements

• 8+ years of software engineering experience with proven ownership of full product areas at startup or staff-level scope.
• Deep backend expertise with FastAPI, Python, and MongoDB (or a comparable stack) in production environments.
• Credible full-stack range: ability to design versioned REST/GraphQL APIs and ship polished React + TypeScript UIs independently.
• Track record of taking ambiguous customer problems to shipped features without a dedicated PM.
• Familiarity with B2B monetization concepts: pricing models, packaging, quoting, billing, or CPQ.
• Experience building or integrating AI-assisted features and agent-driven workflows (LLM interfaces, MCP-like endpoints).
• High standards for correctness, especially in financial and pricing logic.
• Must be authorized to work in the United States; no visa sponsorship available.

Nice to have

• Built MCP servers or tooling for LLM agents.
• Experience with billing, CPQ, or metering systems.
• Prior early employee or co-founder at a 0-to-1 B2B product.
• Familiarity with SOC 2/GDPR constraints.

Pay

Base salary: $200,000 – $250,000 USD annually. Equity participation expected at founding-team level.

Location

On-site in San Francisco, CA, United States. Remote candidates will not be considered for this role.