Founding Lead AI Engineer

Founding Lead AI Engineer

Our client, a stealth‑mode AI design startup in San Francisco, is hiring a Founding Lead AI Engineer to join their team on a hybrid basis (3 days per week in the Bayside Village office). The company has raised over $35M from top‑tier investors and product/design leaders and is preparing for a public launch in April. This is a rare opportunity to join an exceptionally senior engineering and design team where AI is truly core to the product.

Role Overview

We are seeking a Founding Lead AI Engineer who will own our client’s LLM stack end‑to‑end while remaining a deeply hands‑on individual contributor. The ideal candidate brings an Applied Research background, has worked across both research and production, and is excited to drive AI strategy in close partnership with product and design leadership. This role offers outsized influence on technical architecture, product direction, and company culture.

Responsibilities

• Design, fine‑tune, and deploy open‑source LLMs tailored to high‑impact product use cases.
• Optimize model performance across accuracy, latency, and cost, including experimentation with fine‑tuning, distillation, and prompt strategies.
• Architect and own the full LLM infrastructure, including inference services, evaluation pipelines, and orchestration.
• Implement robust observability for AI systems using Langfuse and OpenTelemetry, defining metrics, traces, and alerting.
• Build and maintain production‑grade services in TypeScript/Node.js and Python that integrate models into the core product experience.
• Develop real‑time and streaming features with WebSockets, Redis, and related technologies.
• Leverage LangChain (or similar frameworks) and ONNX runtimes to compose complex LLM workflows and optimize runtime performance.
• Collaborate closely with product and design leaders to shape the AI roadmap and define “hero” features, turning high‑level concepts into shipped experiences.
• Establish best practices for experimentation, evaluation, and safe deployment of LLM‑powered features.
• Provide technical leadership and mentorship as the AI and engineering teams grow.

Candidate profile

• 6+ years of software engineering experience, including 2–3+ years focused on modern ML/LLMs or Applied AI.
• Demonstrated applied research experience in ML/NLP, with a track record of taking ideas from experimentation into production systems.
• Hands‑on experience fine‑tuning or adapting open‑source LLMs (e.g., instruction‑tuning, RAG, distillation, domain adaptation) for real products.
• Deep understanding of accuracy, latency, and cost trade‑offs, with experience optimizing inference performance at scale.
• Very full‑stack builder comfortable working across model experimentation, backend services, data, and production reliability.
• Practical experience with several of the following: Langfuse, OpenTelemetry, LangChain, ONNX, WebSockets, Redis.
• Strong programming skills in TypeScript/Node.js and Python, with an ability to ship clean, reliable, well‑tested code.