Senior Machine Learning Engineer II, Search & Recommendations Ranking

ABOUT THE ROLE We're transforming the grocery industry at Instacart, and we're looking for a talented Machine Learning Engineer to join our Search & Personalization team. As a leader in this field, you'll be responsible for architecting the ranking backbone that unifies query understanding, personalization, multi-objective ranking, ads, and merchandising into a single adaptive platform. Our team is passionate about delivering state-of-the-art multi-task, multi-objective ranking that optimizes for incremental GTV, basket lift, and retention over the long run. WHAT YOU'LL DO As a Machine Learning Engineer on our team, you'll be responsible for designing and building a search autosuggest system optimized for personalization and value-based relevance. You'll also design long-horizon objective functions and build uplift/causal value models that move beyond short-term engagement. Additionally, you'll develop production-grade Multi-Task Learning to jointly learn relevance, propensity, margin, and churn risk, ensuring calibration, constraints, and explainability. You'll also own the inference layer, including goal-aware re-rankers, diversity and quality constraints, safe exploration, and millisecond-class latency optimization. WHAT YOU'LL NEED To be successful in this role, you'll need a strong background in Machine Learning, with 5+ years of experience applying ML at scale. You'll have a proven track record improving ranking or recommendation systems in production, and you'll be able to demonstrate success in applying multi-objective or constrained optimization to balance relevance, revenue, margin, and user experience. You'll also need strong coding skills in Python and data fluency in SQL/Pandas, as well as expertise in classic ML techniques and deep learning frameworks. WHY REMOTE Instacart is a Flex First team, which means we offer flexible work arrangements that allow you to choose where you do your best work. Whether that's from home, an office, or your favorite coffee shop, you'll have the freedom to work in a way that suits you best. Our team is connected and collaborative, and we prioritize regular in-person events to build community and connection. BENEFITS Instacart provides highly market-competitive compensation and benefits in each location where our employees work. This role is remote, and the base pay range for a successful candidate is dependent on their permanent work location. Please review our Flex First remote work policy here.