Machine Learning Engineer

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 first ML engineer, you'll build and own ML models personalization in onboarding and user targeting 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:

• Lead the design, development, and productionization of ML models that power user acquisition, activation, and retention (e.g., ranking models, targeting systems, uplift modeling).
• Own the full model lifecycle: from data collection and feature engineering to model training, evaluation, deployment, and online experimentation.
• Identify and prioritize high-impact opportunities where machine learning can unlock growth, collaborating with product, engineering, data, and marketing stakeholders.
• Drive technical excellence and establish ML best practices across the Buyer Growth team.

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.

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

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

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

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

• Strong communication and leadership skills; ability to influence roadmap and align cross-functional teams.

• Preferred Qualifications:

• Experience building ML applications in E-commerce or Social products
• Prior experience in growth domains: user segmentation, retention modeling, large scale recommendation systems, notification ranking, etc.

• Flexible Time off Policy and Company-wide Holidays (including a spring and winter break)
• Health Insurance options including Medical, Dental, Vision
• Work From Home Support

• Home office setup allowance
• Monthly allowance for cell phone and internet

• Care benefits

• Monthly allowance for wellness
• Annual allowance towards Childcare
• Lifetime benefit for family planning, such as adoption or fertility expenses

• Retirement; 401k offering for Traditional and Roth accounts in the US (employer match up to 4% of base salary) and Pension plans internationally
• Monthly allowance to dogfood the app

• All Whatnauts are expected to develop a deep understanding of our product. We're passionate about building the best user experience, and all employees are expected to use Whatnot as both a buyer and a seller as part of their job (our dogfooding budget makes this fun and easy!).

• Parental Leave

• 16 weeks of paid parental leave + one month gradual return to work *company leave allowances run concurrently with country leave requirements which take precedence.

Whatnot is the largest livestream 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.