Machine Learning Engineer, Growth

About the role

🚀 Join the Future of Commerce with Whatnot!

Whatnot is the largest live shopping platform in North America and Europe to buy, sell, and discover the things you love. Whether it's trading cards, fashion, electronics, or live plants, our sellers are building real businesses across hundreds of categories. We're building live commerce at a scale that's never been done in the West, and there's no playbook to copy. The people here are shaping how an entirely new industry develops.

As a remote co-located team, we're inspired by our values and anchored in hubs across the US, UK, Ireland, Poland, Germany, and Australia. We move fast, stay close to our users, and focus on the work that drives the most impact.

We're one of the fastest growing marketplaces and were recently named the #1 Best Startup Employer in America by Forbes. Check out the latest Whatnot updates on our news and engineering blogs and join us as we enable anyone to turn their passion into a business and bring people together through commerce.

💻 Role

The Buyer Growth team is responsible for driving Whatnot’s top-of-funnel growth and first-time buyer success. We're looking for a Machine Learning Engineer to accelerate buyer growth at Whatnot through intelligent, data-driven experiences. As the second ML engineer on the team, you’ll build and own ML personalization models for user retention in our acquisition and engagement channels. This is a high-impact role on a team directly responsible for growing Whatnot’s buyer base and improving first-time user conversion.

What you'll do:

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Lead the design, development, and productionization of ML models that power user acquisition, activation, and retention (e.g., ranking models, targeting systems, uplift modeling).

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Own the full ML lifecycle. Build and own data pipelines, feature engineering, model training, deployment, and online experimentation. Build feedback loops from postbacks, conversions, and downstream revenue signals.

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Identify and prioritize high-impact opportunities where machine learning can unlock growth, collaborating with product, engineering, data, and marketing stakeholders.

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Drive technical excellence and establish ML best practices across the Buyer Growth team.

👋 You

Curious about who thrives at Whatnot? We’ve found that low ego, a growth mindset, and leaning into action and high impact goes a long way here.

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5+ years of industry experience building and deploying ML systems at scale.

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Demonstrated success in leading end-to-end ML projects that drove measurable business outcomes.

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Deep expertise in personalization, ranking, or user modeling; strong intuition around user behavior in consumer products.

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Advanced proficiency in Python, SQL, and common ML frameworks (e.g., PyTorch, TensorFlow, XGBoost).