Senior Machine Learning Engineer II, Fulfillment, Matching and Positioning

We're transforming the grocery industry At Instacart, we invite the world to share love through food because we believe everyone should have access to the food they love and more time to enjoy it together. Where others see a simple need for grocery delivery, we see exciting complexity and endless opportunity to serve the varied needs of our community. We work to deliver an essential service that customers rely on to get their groceries and household goods, while also offering safe and flexible earnings opportunities to Instacart Personal Shoppers. Instacart has become a lifeline for millions of people, and we’re building the team to help push our shopping cart forward. If you’re ready to do the best work of your life, come join our table. Instacart is a Flex First team There’s no one-size fits all approach to how we do our best work. Our employees have the flexibility to choose where they do their best work—whether it’s from home, an office, or your favorite coffee shop—while staying connected and building community through regular in-person events. Learn more about our flexible approach to where we work. Overview Instacart’s Logistics organization powers the intelligence and execution behind our fulfillment system. We’re hiring a Senior Machine Learning Engineer to join the Matching & Positioning team, a tight-knit group of 9 engineers and scientists focused on real-time decisioning for order batching, shopper routing, and assignment across a dynamic, multi-sided marketplace. In this role, you’ll work at the intersection of operations research, combinatorial optimization, and machine learning to design and ship algorithms that directly impact profitability, on-time delivery, shopper experience, and customer satisfaction at scale. You’ll collaborate closely with engineering, product, and data science partners to translate ambiguous problems into well-formed optimization and ML systems that operate under sub-second latency and high throughput. If you thrive in a fast-paced environment, enjoy rolling up your sleeves, and want to see your models make decisions in the real world every minute of every day, this team is for you. About the Job You will build production-grade optimization and ML solutions that drive Instacart’s fulfillment decisions end-to-end in a rapidly evolving, high-scale environment. Design, implement, and deploy algorithms for order batching, real-time shopper assignment, routing, and marketplace positioning using techniques such as MIP/CP-SAT, heuristics/metaheuristics, and learning-to-rank. Own the full model lifecycle: problem formulation, data pipelines and features, offline evaluation and simulation, A/B testing, staged rollouts, and ongoing monitoring/observability. Build reliable, low-latency services in Python (and, where performance dictates, C++ or Go) that integrate with solvers (e.g., OR-Tools, Gurobi, CPLEX) and run on cloud infrastructure with Docker/Kubernetes. Partner with product, operations, and data science to define roadmaps and success metrics; deliver measurable impact to on-time rates, shopper utilization, cost per order, and customer experience. Leverage experimentation and causal methods along with offline counterfactual replay/simulation to validate changes and de-risk launches. Contribute to engineering excellence through code reviews, design docs, robust testing, and participation in an on-call rotation for mission-critical fulfillment services; mentor peers and raise the technical bar. This is a fast-moving domain with evolving constraints and objectives. Success requires comfort with ambiguity, pragmatic prioritization, and a bias toward iterative learning and continuous improvement. About You You pair a deep toolkit in operations research and machine learning with strong software engineering fundamentals. You’re motivated by real-world impact, communicate clearly with cross-functional partners, and take ownership from ideation to production. Minimum Qualifications Bachelor’s degre