Machine Learning Engineer, Growth

Whatnot; San Francisco (CA); On-site; USD 120,000 - 160,000; Full time

Benefits offered by this job

Flexible Time off Policy

Health Insurance

Work From Home Support

Care benefits

Retirement plan and 401k matching

Parental Leave

Job summary

Whatnot is seeking a Machine Learning Engineer to join our Buyer Growth team in San Francisco. In this role, you will lead the design and development of ML models to drive user acquisition and retention. The ideal candidate has over 5 years of experience in building and deploying machine learning systems and expertise in personalization and ranking. You will have the opportunity to directly impact buyer growth and enhance user engagement across our platform. Benefits include flexible time off, health insurance, and a supportive work-from-home policy.

Qualifications

• 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.

Responsibilities

• Lead the design, development, and productionization of ML models.
• Own the full model lifecycle: from data collection to online experimentation.
• Identify and prioritize high-impact opportunities for machine learning.

Skills

Machine Learning

Python

SQL

Data-driven decision making

Cross-functional collaboration

Tools

PyTorch

TensorFlow

XGBoost

Job description

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 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.

You

• 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.

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
  • 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.

EOE

Whatnot is proud to be an Equal Opportunity Employer. We value diversity, and we do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, parental status, disability status, or any other status protected by local law. We believe that our work is better and our company culture is improved when we encourage, support, and respect the different skills and experiences represented within our workforce.