Founding Engineer

Role details

ABOUT THE ROLE Join a small, high-velocity founding team building multi-modal AI agents across voice, SMS, and email for a vertical B2B SaaS platform that reached seven figures ARR within months of launch. As a Founding Engineer, you'll own one of four core domains end-to-end — B2B product, agent quality, family graph infrastructure, or B2C consumer product — and make product decisions directly alongside customers with no PM layer between you and the work. WHAT YOU'LL DO - Own an entire product domain from architecture through daily production shipping. - Join customer calls, synthesize feedback, and drive product decisions independently. - Build and optimize multi-modal agents targeting sub-500ms voice latency, high SMS response rates, and persistent conversation state across channels. - Establish architecture and quality practices for non-deterministic systems — evals, prompt versioning, guardrails, and drift detection. - Work full-stack across React/Next.js frontends, Node.js backends, and Python voice services. WHAT WE'RE LOOKING FOR - 3–8 years of full-stack engineering experience with a strong record of shipping 0-to-1 products at high-growth startups, as a founder, or within new vertical teams at large tech companies. - Strong proficiency in TypeScript (Node.js, React/Next.js) and hands-on production experience with LLM APIs or agent SDKs (e.g. Anthropic, OpenAI, Vercel AI SDK, or similar). - Depth in at least one domain: production voice/SMS agents, long-running agent state and memory, B2B2C or marketplace product architecture, or agent evals and guardrails. - Demonstrated ability to make product decisions independently and conduct customer discovery without a dedicated PM. - Python experience with real-time voice pipelines (STT/TTS, low-latency audio) or evaluation tooling is a strong plus. - Experience with infrastructure tooling such as Redis, job queues, observability platforms, or deployment pipelines is a plus. - Founder background with real traction (revenue, funding, or acquisition) and clear articulation of lessons learned is a plus. - Strong CS fundamentals; a degree from a rigorous CS program is a plus for candidates earlier in their career. - Must be authorized to work in the US — no visa sponsorship available. COMPENSATION & BENEFITS Salary range: $180,000 – $250,000 USD annually, plus equity. No visa sponsorship is available. LOCATION On-site, five days per week in Chelsea, New York City.