Founding Engineer

About the Role This is a founding engineering seat on a small, fast-moving team building multi-modal AI agents across voice, SMS, and email for the sports and youth-activity industry. You'll own one of four core domains end-to-end — B2B product, agent quality, family graph infrastructure, or B2C consumer product — and work directly with customers to shape the product without a dedicated PM layer. What You'll Do Own an entire product domain from architecture to daily production deploys. Join customer calls, synthesize feedback, and make independent product decisions. Build and optimize multi-modal agents targeting sub-500ms voice latency, high SMS response rates, and persistent conversation state across channels. Drive architecture and quality standards for non-deterministic systems, including 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 shipping 0-to-1 products at high-growth startups, top-tier tech companies, or as a founder. Production proficiency in TypeScript with hands-on experience in Node.js, React, and Next.js. Hands-on production experience with LLM APIs or agent SDKs (Anthropic, OpenAI, Vercel AI SDK, Mastra, LangGraph, or similar) — not just tutorials or prototypes. Depth in at least one area: production voice/SMS agents, long-running agent state and memory, B2B2C or marketplace product architecture, or agent evals and guardrails. Comfortable making product decisions independently and running customer discovery without PM support. Python experience with real-time voice pipelines (LiveKit, Deepgram, STT/TTS) or evaluation tooling (LLM-as-judge frameworks) is a strong plus. Familiarity with infrastructure tools such as Redis, BullMQ, Vercel, Render, Sentry, or PostHog is a plus. Founder background with demonstrated traction (revenue, funding, or acquisition) and clear learnings from failure is valued but not required. No visa sponsorship available; must be authorized to work in the US. Compensation & Benefits Base salary $180,000 – $250,000 annually, plus equity. No visa sponsorship is available. Location On-site five days per week in New York City, NY (Chelsea). Remote arrangements are not available for this role.