Machine Learning Engineer, Growth

Join Whatnot’s Buyer Growth team and help drive measurable improvements in buyer onboarding and first-time conversion. This role focuses on building and owning machine learning models for personalization across acquisition and engagement channels, with end-to-end responsibility from data to production and experimentation.

What you’ll do

• Design, develop, and productionize ML models that support user acquisition, activation, and retention, including ranking models, targeting systems, and uplift modeling.
• Own the full ML lifecycle: build and maintain data pipelines, feature engineering workflows, model training, deployment, and online experimentation.
• Create and maintain feedback loops using postbacks, conversions, and downstream revenue signals to continuously improve model performance.
• Find and prioritize high-impact growth opportunities for machine learning, partnering with product, engineering, data, and marketing stakeholders.
• Lead technical excellence by establishing ML best practices across the Buyer Growth team.

What you bring

• 5+ years of industry experience building and deploying ML systems at scale.
• Proven ability to lead end-to-end ML projects and deliver measurable business outcomes.
• Deep expertise in personalization, ranking, or user modeling, with strong intuition for user behavior in consumer products.
• Advanced proficiency in Python and SQL, plus common ML frameworks such as PyTorch, TensorFlow, and XGBoost.
• Strong communication and leadership skills, with experience influencing roadmaps and aligning cross-functional teams.
• Preferred: experience building ML applications in E-commerce or Social products.
• Preferred: experience in growth domains such as user segmentation, retention modeling, large-scale recommendation systems, and notification ranking.

Tech stack

• Python, SQL, PyTorch, TensorFlow, XGBoost

What Whatnot offers

• Flexible Time Off policy and company-wide holidays, including spring and winter break.
• Health Insurance options: Medical, Dental, Vision.
• Work From Home support plus home office setup allowance.
• Monthly allowances for cell phone and internet, and a wellness allowance.
• Care benefits and an annual allowance toward 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 of gradual return to work.

Location: Seattle, WA (remote)
Compensation Range: $190K - $280K per year
EOE