Founding Engineer

As a founding engineer, you’ll take full ownership of a core domain, make product calls without a PM, and ship to production daily alongside a small, high-velocity team working in person in New York.

What you’ll be doing

• Own a core product domain end-to-end (for example the B2B business platform, the voice/SMS/email agent layer, the underlying data/AI graph, or a new consumer product)
• Talk directly to customers, turn their feedback into product decisions, and ship the work yourself
• Build and tune multi-modal agents for low-latency voice, strong messaging response rates, and durable conversation state across channels
• Set the architecture and quality bar for non-deterministic systems: evals, prompt versioning, guardrails, and drift detection
• Work across the full stack, from React/Next.js on the front end to Node.js services and Python voice pipelines

Tech stack: TypeScript, Node.js, Next.js, React, Python, LiveKit, Deepgram, Redis, plus modern LLM and agent tooling (Anthropic/OpenAI SDKs, Vercel AI SDK, Mastra, Braintrust)

• 3-8 years of full-stack engineering experience
• Track record shipping a product from zero to one, whether at a high-growth startup, as a founder, or on a new-product team inside a larger company
• Strong command of TypeScript across the stack (Node.js and React/Next.js)
• Comfortable owning product decisions without a PM, including speaking directly with customers
• Real, hands-on depth in at least one relevant area: production voice or SMS agents, long-running agent state and memory, B2B2C or marketplace products, or agent evaluation and guardrails
• Genuine product experience building with LLM APIs or agent SDKs (not tutorials or thin wrappers)

Nice to Haves

• Prior experience as a founder or at an accelerator-backed startup that gained real traction, with the perspective to reflect on what worked and what didn’t
• Degree from a strong computer science program (weighed more heavily for candidates at the earlier-career end of the range)
• Python experience with real-time voice pipelines (LiveKit, Deepgram, STT/TTS) or with evaluation tooling

• Join at the founding stage and own an entire domain from day one
• Work directly with an experienced founding team in a fast-moving, high-ownership environment
• Strong early traction in a large market with room to grow into leadership or stay on a deep IC track
• Competitive salary plus meaningful founding equity

Our client is a stealth-stage AI startup building multi-modal agents (voice, SMS, and email) that automate operations end-to-end for a large, under-digitized consumer-services industry. Founded by engineers who previously helped scale high-growth consumer platforms, the team has already found strong early product-market fit and is growing fast. This is an early founding-team seat with the chance to own a full product domain from day one.

Founded 2024 · Small Team · Industry: AI, Marketplace, Consumer, B2B, Education