Machine Learning Engineer, Growth

Whatnot’s Buyer Growth team is focused on improving how new buyers discover value and convert over time, with machine learning at the center of that effort. As a Machine Learning Engineer, you will build and take ownership of models that support personalization across onboarding and user targeting, spanning acquisition and engagement channels to drive buyer growth and improve first-time conversion.

What you’ll do

• Design, develop, and productionize machine learning models for user acquisition, activation, and retention, including ranking models, targeting systems, and uplift modeling.
• Own the end-to-end ML lifecycle: build and maintain data pipelines, perform feature engineering, train models, deploy them, and run online experimentation.
• Create feedback loops that connect postbacks, conversions, and downstream revenue signals back into model and product iteration.
• Find and prioritize high-impact growth opportunities where machine learning can unlock measurable results, working closely with product, engineering, data, and marketing partners.
• Drive technical excellence by establishing ML best practices across the Buyer Growth team.

What you bring

• 5+ years of industry experience building and deploying machine learning systems at scale.
• Proven experience leading end-to-end ML projects that delivered measurable business outcomes.
• Deep expertise in personalization, ranking, or user modeling and strong intuition for user behavior in consumer products.
• Advanced proficiency in Python, SQL, and common ML frameworks such as PyTorch, TensorFlow, and XGBoost.
• Strong communication and leadership skills, with the ability to influence roadmap decisions and align cross-functional teams.
• Preferred: Experience building ML applications in e-commerce or social products.
• Preferred: Prior growth-domain experience such as user segmentation, retention modeling, large-scale recommendation systems, and notification ranking.

Technologies

• Python
• SQL
• PyTorch
• TensorFlow
• XGBoost

Location and compensation

Seattle, WA (remote). Compensation range: USD 190,000 - 280,000 per year. Minimum experience: 5 years. EOE.

Benefits

• 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
• Parental Leave: 16 weeks of paid parental leave plus one month gradual return to work