Machine Learning Engineer (Foundation Models & Personalization)

The role

You will build and ship consumer-facing AI systems for personalization, coaching, and sleep intelligence. You will work across data, modeling, product, and engineering to translate research into measurable improvements for members.

What you will do

• Build and deploy ML models for personalization, prediction, and behavior understanding.
• Apply and adapt foundation-model capabilities to real product workflows.
• Develop user behavior models connecting longitudinal signals to actionable interventions.
• Design evaluation strategies and partner with Product to run online experiments.
• Productionize models including scalable training/inference pipelines and monitoring.
• Collaborate with cross-functional partners to scope requirements and ship features.

Required qualifications

• 2+ years building ML systems in production, ideally for consumer-facing products.
• Strong ML fundamentals across supervised learning, sequence/time-series modeling, and modern deep learning.
• Hands-on experience with large-scale model training and evaluation (PyTorch/TensorFlow/JAX).
• Strong Python engineering practices.
• Experience with personalization systems (ranking/recommendations, segmentation, lifecycle modeling, propensity/behavior modeling, causal/experiment-aware thinking).
• Fluency with data tooling (SQL, distributed compute such as Spark/Ray, and cloud storage/compute).
• Strong product sense to translate ambiguous goals into measurable outcomes.

Nice to have

• Experience applying LLMs/foundation models to product features (tool use, retrieval, structured outputs, guardrails, evals).
• Experience with multimodal data (sensor signals + context) and/or health/biometrics data.
• Experience with privacy-preserving approaches (on-device/federated learning, differential privacy, data minimization).
• Experience designing experimentation frameworks or causal inference approaches for personalization.

Benefits

• Equity participation for every full-time team member.
• Periodic equity refreshments based on performance.
• A Pod product.

About the company

Eight Sleep is a sleep fitness company building hardware, software, and AI technology to transform sleep into a personalized, data-driven recovery experience.