Lead AI/ML Engineer

About the role

Sandbar, a New York‑based interface company, is building Stream – a private voice ring and conversational interface that extends human thinking. As the Lead AI/ML Engineer you will own the end‑to‑end design, development and deployment of the ML components that power agentic control, multimodal interaction and information retrieval.

Key responsibilities

• Define architecture, strategy and trade‑offs for ML‑based products.
• Design and improve user‑facing model experiences, including conversational and retrieval capabilities.
• Build infrastructure for rapid model development, evaluation and deployment.
• Optimize inference pipelines for latency, reliability and concurrency.
• Collaborate closely with ML/AI engineers, infrastructure engineers, designers and co‑founders.

Required profile

• 6+ years of professional machine‑learning experience.
• Proven track record shipping ML‑driven products.
• Hands‑on experience with large‑language‑model evaluation and post‑training.
• Familiarity with audio/voice ML is a plus.
• Comfortable writing production‑grade software and setting technical direction for multidisciplinary teams.

Required skills

• Large‑language‑model evaluation and post‑training.
• Audio/voice machine‑learning techniques.
• Model inference optimization for low latency and high concurrency.

What we offer

• Health, vision and dental benefits.
• Company‑sponsored 401(k) plan.
• Unlimited PTO and sick time.
• Early‑stage equity participation.