Founding Engineer

About the Role

This is a founding engineering seat at a fast-growing AI-native startup building multi-modal sales agents across voice, SMS, and email for a focused vertical market. You will own one of four core domains end-to-end, making product and architecture 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, covering areas such as B2B product, agent quality, family graph infrastructure, or B2C consumer product.

• 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.

• Design and maintain quality systems for non-deterministic AI behavior, including evals, prompt versioning, guardrails, and drift detection.

• Work full-stack across React/Next.js frontends, Node.js backends, and Python voice and real-time services.

What We're Looking For

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

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

• Direct production experience building with LLM APIs or agent SDKs such as Anthropic, OpenAI, Vercel AI SDK, or Mastra.

• 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 PM support.

• Experience with low-latency system design and non-deterministic system behavior at production scale.

• Python experience with real-time voice pipelines (such as LiveKit or Deepgram) or evaluation tooling is a strong plus.

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

• Strong CS fundamentals, with a relevant degree or verifiable founder traction (revenue, funding, or acquisition) serving as a positive signal for candidates earlier in their career.

• No visa sponsorship is available for this role.

Compensation & Benefits

Base salary: $180,000 to $250,000 USD annually. Equity is available given the founding nature of the role. Visa sponsorship is not available.

Location

On-site, five days per week in Chelsea, New York City. Candidates must be based in or able to commute to NYC.