Senior Machine Learning Engineer, Search & Recommendations Ranking

<div class="content-intro"><p><strong>We're transforming the grocery industry</strong></p> <p><span class="im">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.</span></p> <p>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.</p> <p><strong>Instacart is a Flex First team </strong></p> <p>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. <a href="https://instacart.careers/remote/" target="_blank" data-saferedirecturl="https://www.google.com/url?q=https://instacart.careers/remote/source=gmailust=1651869232122000usg=AOvVaw37OlxP8hAKN7nq4YwHQH7e">Learn more about our flexible approach to where we work.</a></p></div><p class="chakra-text isc-1e25kok"><strong class="chakra-text isc-1te2462">Overview</strong></p> <p class="chakra-text isc-1e25kok">This is a general posting for multiple Senior Machine Learning roles open across our 4-sided marketplace. You’ll get the chance to learn about the problems the different ML teams solve as you go through the process. Towards the end of your process, we’ll do a team-matching exercise to determine which of the open roles/teams you’ll join. You can find a blurb on each team at the bottom of this page.</p> <p class="chakra-text isc-1e25kok">The Search Recommendations ML team is Instacart’s engine for multi-task, multi-objective ranking—unifying search, discovery, ads, and merchandising into a single value-aware platform. Partnering with world-class engineers, scientists, and PMs, we build the ranking backbone that powers every pixel of the shopping journey, optimizing not just for clicks, but for incremental GTV, basket lift, and retention over the long run.</p> <p class="chakra-text isc-1e25kok"><span class="chakra-text isc-1te2462">What We’re Building</span></p> <ul class="isc-172rq0g"> <li class="isc-v0v4r7"><span class="chakra-text isc-1te2462">Foundational Ranking Backbone Models:</span> Multi-task/multi-objective models (shared encoders + task heads) that jointly learn relevance, conversion, margin contribution, churn risk, and ad quality, enabling consistent decisions across search and recommendations.</li> <li class="isc-v0v4r7"><span class="chakra-text isc-1te2462">Value-Aware Optimization:</span> Uplift and long-horizon value models that steer decisions toward incrementality and LTV, with calibrated constraints on quality, diversity, fairness, and spend pacing—plus guardrails for safe exploration.</li> <li class="isc-v0v4r7"><span class="chakra-text isc-1te2462">LLM-Enhanced Retrieval Features:</span> Using LLMs to enrich query and item semantics for long-tail recall, generate features for cold-starts, and feed the ranker with reasoning-rich context, while remaining the source of truth for final ordering.</li> </ul> <p class="chakra-text isc-1e25kok">Our commitment to AI innovation is reflected in our recent publications and research contributions to the field.</p> <p class="chakra-text isc-1e25kok"> </p> <p class="chakra-text isc-1e25kok"><strong class="chakra-text isc-1te2462">About the Job</strong></p> <ul class="isc-172rq0g"> <li class="isc-v0v4r7">Architect the ranking backbone that unifies query understanding, personalization, multi-objective ranking, ... (truncated, view full listing at source)