Founding Engineer

About the Role

This is a founding engineering seat at a fast-growing AI-native startup building multi-modal agents across voice, SMS, and email for a vertical B2B2C market. You will own one of four core domains end-to-end, B2B product, agent layer 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 long-running conversation state across channels.

• Define the quality bar 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 to 8 years of full-stack engineering experience, with a strong track record shipping 0-to-1 products at high-growth startups, as a founder, or within new vertical teams at top-tier tech companies.

• Production proficiency in TypeScript with hands-on experience in Node.js and React/Next.js.

• Proven experience building with LLM APIs or agent SDKs (such as Anthropic, OpenAI, Vercel AI SDK, or Mastra) in production systems.

• Depth in at least one area: production voice or SMS agents, long-running agent state and memory, B2B2C or marketplace product architecture, or agent evals and guardrails.

• Comfort making independent product decisions and conducting customer discovery without dedicated product management support.

• Python experience with real-time voice pipelines (LiveKit, Deepgram, STT/TTS) or evaluation tooling (Braintrust, LLM-as-judge) is a strong plus.

• Familiarity with infrastructure tools such as Redis, BullMQ, Vercel, Render, Sentry, or PostHog is a plus.

• Strong CS fundamentals, a founder background with verifiable traction, or experience at a well-regarded AI-native employer rounds out the profile.

• Thrives in ambiguous, early-stage environments; prefers defining processes over following them.

• No visa sponsorship available.

Compensation & Benefits

Salary range: $180,000 to $250,000 USD annually. Equity is available given the founding-team nature of this role. No visa sponsorship is available.

Location

On-site, five days per week in New York City, New York, USA (Chelsea area).