Lead AI/ML Engineer

Sandbar; New York (NY); On-site; USD 180,000 - 240,000; Full time

Job summary

Sandbar, an interface company in New York City, is seeking a Lead ML Engineer to build Stream, a private voice ring and conversational interface. You will architect, deploy, and optimize a new multimodal, agentic interface with strong emphasis on real-world ML deployment and human-in-the-loop systems.

You will lead technical direction, collaborate with ML/AI engineers, infrastructure, and design teams, and drive end-to-end model development from research to production at scale.

Qualifications

• 6+ years of post-graduate machine learning experience.
• Experience shipping ML-based products is required.
• Experience in large-language model evaluation and post-training is required.
• Audio/voice ML experience is a plus.
• Comfortable writing production-grade software.
• Passion for human-computer interaction.
• Experience setting technical direction and driving execution with multidisciplinary teams.

Responsibilities

• Lead architecture, strategy, and tradeoffs for ML-based products.
• Design and improve user-facing model-based experiences, incl. agentic control, conversational interactions, and information retrieval.
• Develop infrastructure to rapidly develop, evaluate, and deploy models.
• Optimize inference pipelines for latency, reliability, and concurrency.
• Collaborate with ML/AI engineers, infra, design, and cofounders on current and future products.

Skills

Senior ML leadership

ML-based product shipping

LLM evaluation & post-training

Audio/voice ML (plus)

Production-grade software

Human-computer interaction

Technical direction & execution

Job description

Sandbar is an interface company in New York City. We aim to augment individuals so we can each think, act, and move more freely. Our team has built SW, ML, and HW products across Meta, CTRL-labs, Google, Apple, Fitbit, Peloton, and Equinox.

Our first product, Stream, is a self extension—a private voice ring and conversational interface. Stream has been featured in WSJ, Bloomberg, & Wired, and begins shipping in Summer '26.

Join us in creating technology that extends human thinking.

We’re looking for a Lead ML Engineer to build Stream, a new conversational interface. As an ML Lead, you will architect, build, and deploy a new interface which spans agentic control, multimodal interactions, and information retrieval. This role is perfect for someone who cares deeply about real-world ML deployment and human-in-the-loop agentic interactions.

Responsibilities

• Lead architecture, strategy, and tradeoffs for our ML-based products
• Design and improve user-facing model-based experiences, including agentic control, conversational interactions, and information retrieval.
• Develop infrastructure to rapidly develop, evaluate, and deploy models
• Optimize inference pipelines for latency, reliability, and concurrency
• Work closely with other ML/AI engineers, infrastructure engineers, designers, and cofounders on existing and future products

Qualifications

• 6+ years of post-graduate machine learning experience, not including internships
• Experience shipping ML-based products is required
• Experience in large-language model evaluation and post-training is required
• Experience in audio / voice ML is a plus
• Comfortable writing production-grade software
• Passion for human-computer interaction
• Experience setting technical direction and driving execution with multidisciplinary teams