Machine Learning Engineer, Whatnot

• M.S. or Ph.D. in Computer Science, Machine Learning, Economics, Statistics, or equivalent professional experience
• 8+ years of industry experience building software and ML pipelines/systems, including technical leadership (project/tech lead or equivalent)
• Experience in applied statistical and machine learning fields e.g. Ads, search, recommendations, content understanding, natural language processing, and large language models
• Strong proficiency in Python and at least one ML stack (e.g. scikit-learn, PyTorch, LightGBM), plus solid software engineering fundamentals
• Are capable of building scalable systems (we primarily use Python, Elixir, JavaScript)
• Solid backend development skills and experience deploying ML models to production (batch or real-time)
• Experience with data orchestration frameworks (Dagster, Kubeflow) and feature store design
• Experience with data analysis and capable of conducting deep behavioral data analysis to uncover trends within the complex advertising marketplace
• Excellent product instincts. You think first about users rather than the best technical solution. Ability to translate business/product needs into measurable ML solutions and collaborate across diverse cross-functional teams/stakeholders
• A collaborative mindset — especially with other Senior ML ICs on team, product, data science, and cross-functional ML counterparts — to drive measurable business outcomes
• Bonus: Experience in leadership positions (e.g. Technical Lead or Management). Strategic and technical leadership that raises the bar for engineering excellence

Desirable

• Ads+Promos is a growing engineering org at Whatnot that is dedicated to building products and systems to help sellers grow their business, stand out in a competitive marketplace and strengthen their brands
• The Ads Quality team is responsible for ensuring the most relevant, high-performing ads and promotions reach users across all our ad formats and discovery experiences
• This team owns the retrieval and ranking stages in the ads delivery funnel, balancing relevance for users and ROI for advertisers. As we expand into new features & ad formats, this team will be critical to maintaining user trust while scaling advertising revenue
• We're seeking an experienced Machine Learning Engineer who enjoys developing, productionizing models and leading technical direction across teams. In addition, as we grow, this role will have opportunities to extend further into leadership & management responsibilities
• This is a high-impact role where you'll work with other Senior ICs to drive the technical direction, mentor exceptional engineers, and work cross-functionally to build the next generation of ads products. Specifically, you will:
• Lead the design and evolution of machine learning models that power ads retrieval, ranking, and auction systems at scale
• Own end to end ML systems, including training pipelines, feature infrastructure, and low latency online inference for real time and batch use cases
• Apply advanced statistical and ML techniques to improve ads relevance, marketplace efficiency, and Seller outcomes
• Define experimentation strategies, success metrics, and evaluation frameworks, and drive iteration through rigorous offline and online testing
• Establish model and system observability through metrics, dashboards, and reliability best practices
• Provide technical leadership through mentorship, design reviews, and raising engineering standards across the Ads+Promos org and Engineering at Whatnot
• Stay current on advances in machine learning and ads auction systems, and drive adoption where they deliver clear impact