Senior Machine Learning Engineer

About Grubhub

At Grubhub, we believe food is more than just a meal:
It’s a source of discovery, connection, and pure enjoyment. There’s a time and place for every type of dish, from hidden neighborhood gems to tried-and-true favorites, and we exist to connect people with the food they love in all the ways they like to dig in. We’ve been at it since 2004, but now, as part of Wonder, Grubhub is operating with a renewed sense of momentum and the high-velocity energy of a powerhouse startup.

As a leading U.S. ordering and delivery marketplace, we feature over 415,000 merchants in more than 4,000 cities, creating the ultimate food experience by elevating online ordering through innovative restaurant technology, easy-to-use platforms, and an improved delivery experience. We are constantly finding new ways to innovate—from integrated grocery delivery with groceries powered by Instacart to exclusive loyalty programs. Join our team, based out of New York City, Chicago and Denver, and help us give our diners the exceptional value they deserve.

Grubhub is looking for a Senior Staff Machine Learning Engineer to help lead the machine learning engine behind Discovery: the ranking, recommendation, and retrieval systems that decide what every diner sees when they open the app or run a search. These models sit on the critical path to conversion for hundreds of thousands of merchants and hundreds of millions of menu items, and they are one of the largest organic growth levers we have.

This is a hands‑on technical leadership role, not a management role. You will own model architecture across several connected technical areas: search ranking, homepage and topic recommendations, retrieval, and query understanding. You will be accountable for how those pieces fit together, not only for any single model.

You will set technical direction alongside other staff engineers, product managers, and platform partners. You will raise the bar on how the organization builds, evaluates, and operates models, and mentor the engineers around you through design reviews, code reviews, and direct feedback. We expect you to challenge technical decisions across teams when the engineering case is clear, and to bring evidence when you do.

Our team practices end to end project ownership, and our work focuses heavily on personalized recommendation, retrieval, and classification from catalog content and clickstream. Deep neural networks, learned embeddings and approximate nearest neighbor retrieval, transfer learning from pre‑trained large scale models, calibration, classic regressions, fine tuning, and large language models all have a place in our daily lexicon.

• Own the architecture of our ranking and recommendation stack end to end: candidate retrieval, multi‑objective ranking, calibration, and the ensemble that trades conversion against profitability. Make the cross‑system design calls that no individual model owner can make alone.
• Lead the evolution of our optimization objective from short‑term conversion toward long‑term diner value, including the offline evaluation and online experimentation work required to trust the result before it ships.
• Bring state of the art research in information retrieval and recommender systems into our runtime environment: LLM‑driven query and intent understanding, embedding‑based retrieval, sequential user representations for cold start, and real‑time inference. Assess rigorously what actually transfers to our traffic, and say no to what does not.
• Raise engineering and operational standards across multiple teams: model evaluation and scorecards, reproducible training pipelines, safe deployment, SLOs and observability for tier‑1 models, and proactive management…