About Trainwell

Trainwell stands out in the crowded fitness market by delivering accountability and genuine human support via 1-on-1 remote personal training. Trainwell’s key differentiation is its trainer operations and AI-enabled trainer scaling tech, which augments its skilled trainers’ time and empowers them to work with 10X more clients at once than traditional trainers without compromising quality. This scalability enables strong margins at prices 5X lower than in-person training and 2x lower than direct competitors.
Founded in 2019 by Carnegie Mellon hackathon world champion Matt Spettel (CEO) and MIT machine learning researcher Gabe Madonna (CTO).
Raised $19M and scaled to 8-figure ARR with a lean world-class team.
Distribution partnership signed with leading connected fitness brand which alone represents $30M in new ARR opportunity in 2026.

About This Role

You will be part of our direct-to-consumer growth team and report directly to Matt Spettel, CEO.
Your primary objective will be to drive top-line ARR growth by engineering systems that help the growth team iterate faster and make more data-driven decisions.
You will build systems to ingest, analyze, summarize growth data - and display that data using PostHog and our internal React-based dashboard.
You will train models that predict high leverage outputs such as the performance of marketing campaigns and the retention of certain users.
You will build automated systems that leverage LLMs to help supplement growth data and streamline internal growth processes.
You will maintain and expand our in-house A/B testing infrastructure and help implement and facilitate A/B tests across our marketing, onboarding funnel, and product.

What You Bring

2+ years of experience with data science and machine learning in Python.
A track record of taking high ownership over projects and building tools/products outside of work and school that solve real problems.
Experience with building data pipelines and dashboards in data visualization and aggregation tools like Mixpanel and Posthog. Any experience building full-stack web applications in Typescript/React is a plus.
Familiarity with common consumer startup growth challenges, strategies, and A/B testing methodology.
Bachelors or higher in computer science or electrical/computer engineering.

Our culture is fun and casual, but we work very hard. From passion projects to hackathons, we are people who take a lot of ownership over our work and aren't afraid to get our hands dirty and build things fast. Our team is motivated not by deadlines or paychecks, but by the life changing impact that our product has on hundreds of thousands of people around the world.

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