Sandbar builds the Stream smart ring and companion app that let users capture and interact with AI-powered voice notes on the go.
About Sandbar 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. About 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 in machine learning experience - 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 FTE Benefits - Health, vision, and dental benefits - Company-sponsored 401(k) - Unlimited PTO and sick time - Early stage equity