Staff AI Engineer

Tonal • San Francisco, CA

39d

About The Position

Tonal is looking for an AI Engineer to help expand Tonal's intelligence across movements, training modalities, and member goals. You'll be joining a high impact team at the intersection of machine learning, biomechanics, and product engineering. You will be responsible for building intelligent systems that adapt workouts, enhance coaching, and personalize progression using the largest strength training dataset in the world. With millions of workouts collected across diverse users and enriched by data from cameras, cable sensors, and external trackers, Tonal has a one of a kind platform for real world AI. You will help transform this data into production grade models and systems that deliver real time insights, predictions, and feedback to our members.

Requirements

• A self driven AI or ML Engineer passionate about bringing applied machine learning into real world, user facing products
• 7 plus years of experience in software engineering or applied ML, or 5 plus with a Master's degree, or PhD with 3 plus years of experience
• Strong coding skills in Python and experience with frameworks such as PyTorch, TensorFlow, or JAX
• Experienced in ML training, evaluation, and deployment workflows such as Sagemaker, MLFlow, Databricks, or similar
• Deep understanding of time series modeling, human motion, or sensor based learning from devices such as force transducers, position encoders, IMUs, or cameras
• Familiar with MLOps best practices and scalable model training pipelines
• Strong communicator who can collaborate with scientists, product managers, and engineers
• Track record of delivering performant ML systems from prototype to production

Nice To Haves

• Experience fine tuning large transformer or multimodal models
• Experience deploying models to real time or edge environments such as on device inference
• Experience with GoLang, Kotlin or Flutter
• Experience with distributed training, mixed precision optimization, or model compression
• Interest in fitness, digital health, or intelligent training systems
• Background in biomechanics, kinesiology, or human performance analytics

Responsibilities

• Design, implement, and optimize machine learning training pipelines and model serving infrastructure for real time applications
• Develop algorithms and ML models that enable personalized training, adaptive coaching, and performance prediction
• Fine tune and evaluate transformer based or self supervised learning models using Tonal's multimodal dataset
• Build data driven systems that measure training effectiveness, effort, and progression beyond traditional weight based metrics
• Prototype, train, and deploy ML models that run efficiently at scale or on device
• Collaborate cross functionally with Exercise Science, Product, and Software teams to deliver intelligent features that improve the member experience
• Contribute to the development of automated tools for experimentation, model validation, and continuous retraining
• Write high quality, maintainable Python code and work closely with backend engineers to integrate models into Tonal's production systems
• Mentor teammates and help shape Tonal's growing AI and ML best practices

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Industry: Amusement, Gambling, and Recreation Industries
• Number of Employees: 5,001-10,000 employees