Principal Applied ML Engineer

About the Role

You will lead the data and applied ML work behind Perifit’s AI strategy. Your scope will cover data foundations, churn and retention models, sensor model improvement and the first building blocks of future AI-powered personalization. You will turn ambiguous business and product questions into clear datasets, metrics, models and production-ready systems.

Concretely, you will define the right data events, cohorts and labels; build pragmatic models that can improve retention and adherence; help improve our sensor models with real-world usage data; and make sure models can be deployed, monitored and maintained in production, including through APIs, backend services or local inference in the mobile app when relevant.

This is a highly cross-functional role. You will work closely with:

• Product, to translate data insights into user-facing features
• Software, to integrate models into production systems
• Research, to connect ML work with biomechanical and symptom data
• OBS and Data Engineering, to structure the datasets, pipelines and operational insights needed to understand users and improve retention