Lead/Principal Machine Learning Scientist - Recommendation Systems

• Join Tripadvisor as a Lead or Principal Machine Learning Scientist for Recommendation Systems, working hybrid from London. • Act as the technical anchor for the core discovery engine in the Trips vertical. • Lead the ML strategy behind how millions of users search for, discover and plan their travel. • Bridge cutting-edge AI research and production-grade engineering. • Tackle problems across multi-task ranking, sequential user modelling and graph-based recommendations. • Mentor and coach a high-performing team of ML scientists.

• Hold a PhD or Master’s degree in Computer Science, Machine Learning, Statistics or a quantitative field. • Bring 8+ years of industry experience deploying large-scale ML models to millions of active users. • Show practical experience with Multi-Task Learning, MMoE or similar multi-objective architectures. • Bring hands-on experience building sequential recommendation systems. • Understand embedding generation, deep semantic retrieval and multi-modal representation learning deeply. • Master Python and deep learning frameworks such as TensorFlow or PyTorch. • Show experience with distributed computing such as Spark or Ray, and cloud platforms such as AWS or GCP.

• Bring strong experience with Graph Neural Networks, knowledge graphs or graph embeddings. • Know agentic AI frameworks, LLM-driven reasoning or autonomous planning agents. • Show experience in e-commerce, travel tech or two-sided marketplaces with constrained inventory. • Bring publications at top AI or IR conferences such as SIGIR, KDD, RecSys or NeurIPS, or open-source ML contributions.

• Drive the technical roadmap for search, retrieval, ranking and recommendation in the Trips vertical. • Turn business goals into concrete ML architectures and scalable production systems. • Design, prototype and scale next-generation recommendation and ranking models. • Oversee low-latency, high-throughput retrieval and ranking pipelines, including vector search. • Optimise multi-task business objectives with Product, Engineering and Data Science partners. • Act as the primary technical authority for ML initiatives in Trips. • Mentor senior and mid-level ML scientists and drive best practice in MLOps and A/B testing.

• Earn a competitive salary plus an annual bonus. • Work flexibly with a remote-friendly approach and a flexible schedule. • Use an annual lifestyle benefit for travel, wellness or anything you choose. • Get tuition assistance and charitable donation matching. • Enjoy travel perks and discounts. • Access an employee assistance programme and health benefits. • Earn generous referral rewards.

Tripadvisor Group connects people to experiences worth sharing and aims to be the world’s most trusted source for travel. Its brands include Tripadvisor, Viator and TheFork, with two-sided marketplaces for experiences, accommodation and restaurants. Tripadvisor helps millions of users search for, discover and organise their travel itineraries.