Senior Machine Learning Scientist (Viator)

Tripadvisor; Greater London; Hybrid; GBP 120,000 - 180,000; Full time

Benefits offered by this job

Competitive compensation

Remote-friendly collaboration

Tuition assistance

Travel perks

Job summary

Tripadvisor, Inc. is seeking a Senior Machine Learning Scientist (Viator) in London to lead ML strategy for discovery components such as search, retrieval and ranking. The role focuses on production-grade engineering, rapid prototyping, and translating research into business KPIs like bookings and engagement.

You will mentor junior scientists, work with engineering on infrastructure, and design robust evaluation and guardrails to ensure scalable, reliable ML systems across global products.

Qualifications

• Master’s or Ph.D. in CS, ML, or a highly quantitative field.
• 5+ years of industry experience developing and deploying large-scale ML models.
• Strong ML theory and practical skills in deep learning, feature engineering, and ranking.
• Experience with SOTA architectures, multi-task learning, Content AI stacks, and related technologies.
• Proficiency in Python and DL frameworks; data versioning and experiment tracking.
• Experience with retrieval pipelines, ranking, and graph-based representations is a plus.

Responsibilities

• Lead ML projects within your pod and design custom model components or loss functions.
• Evaluate architectures for trade-offs between accuracy, inference speed, memory usage, and costs.
• Implement rigorous validation, backtesting, and guardrails to prevent data leakage and production regressions.
• Collaborate with Engineering Leads to ensure infrastructure supports model requirements and deployment.
• Mentor mid-level and associate ML scientists, reviewing experiments for rigor and production suitability.

Skills

ML leadership

Python

PyTorch

Production ML

Model deployment

Experiment tracking

Data versioning

Education

Master's or Ph.D. in CS/ML

Tools

PyTorch Lightning

TensorFlow

Job description

Senior Machine Learning Scientist (Viator)

London, United Kingdom

About Tripadvisor

The Tripadvisor Group connects people to experiences worth sharing, and aims to be the world’s most trusted source for travel and experiences. We leverage our brands, technology, and capabilities to connect our global audience with partners through rich content, travel guidance, and two-sided marketplaces for experiences, accommodations, restaurants, and other travel categories. The subsidiaries of Tripadvisor, Inc. (Nasdaq: TRIP), include a portfolio of travel brands and businesses, including Tripadvisor, Viator, and TheFork.

About the Role

You’ll serve as a key technical lead and pod architect within our core discovery engine. You will independently own and execute the machine learning strategy for major product capabilities—such as Search, Retrieval, Ranking, or Content AI—that power how millions of users discover and plan their travel itineraries.

This Senior Machine Learning Scientist role bridges the gap between state-of-the-art (SOTA) research and robust, production-grade engineering. You will navigate technical ambiguity, implement custom algorithmic components, and explicitly map offline model metrics directly to business KPIs like booking conversion and user engagement. If you are a relentlessly curious scientist who excels at rapid prototyping, practical SOTA deployment, and multiplying the capabilities of your peers, this role is for you.

What You’ll Do

• Technical Leadership & Custom Implementation: Act as the technical lead for specific ML projects within your pod. Design and implement custom model components or loss functions that don't exist "off-the-shelf," breaking down massive research goals into deliverable, iterative milestones.
• Optimization & SOTA Scouting: Evaluate the global research landscape to conduct cost-benefit analyses on new architectures, balancing model complexity against inference speed, memory usage, and execution costs (such as token consumption). Optimize models for production using techniques like quantization and distillation.
• Operational Frameworks & Rigor: Tailor Golden Datasets and leaderboards with minimal supervision, and implement rigorous validation automation (such as backtesting and slice-based evaluation) to prevent data leakage, over‑fitting, and production regressions.
• Engineering Partnership & Handovers: Collaborate closely with Engineering Leads to ensure compute/GPU infrastructure supports model requirements. Clearly define model failure modes, edge cases, and confidence thresholds—to enable SWE partners to build robust fallback systems.
• Applied Debugging & Guardrails: Diagnose complex algorithmic bugs and implement automated checks for "Silent Failures" (e.g., concept drift or production feature distribution shifts). Lead team-level post-mortems and resolve blocking corrective actions.
• Career Multiplier: Formally mentor mid-level and associate ML scientists, reviewing their experimental logic to ensure high scientific rigor while guiding them through applied ML and production constraints.

Skills & Experience

• Education: Master’s or Ph.D. degree in Computer Science, Machine Learning, Statistics, or a highly quantitative field.
• Experience: 5+ years of industry experience developing, validating, and deploying large-scale ML models in production environments.
• Algorithmic Expertise: Strong practical and theoretical foundation in machine learning techniques, feature engineering, and deep learning paradigms.
• SOTA Adaptability: Proven ability to tweak, hybridize, and adapt existing state-of-the-art architectures to solve non-linear business problems. Experience with multi-task learning (MTL), ranking, Content AI stacks, Agentic AI etc is highly desirable.
• Technical Stack: Mastery of Python and deep learning frameworks (such as PyTorch, PyTorch Lightning, or TensorFlow) alongside familiarity with data versioning and experiment tracking tools.
• Next-generation retrieval pipelines, multi-stage ranking systems and Content AI stacks.
• Advanced sequential recommendation systems designed to model real-time user session dynamics.
• Graph Neural Networks (GNNs), knowledge graphs, and multi‑modal representation learning to map travel entities.
• Generative AI and Agentic AI workflows to improve conversational discovery experiences.

What We Offer

• Competitive compensation packages (routinely benchmarked against the latest industry data), including base salary and annual bonuses
• “Work your way” with flexibility to suit your lifestyle. Tripadvisor Group takes a remote-friendly approach to collaboration across a worldwide team, with the option to join on-site as often as you’d like or as required by your team.
• Flexible schedule. Work-life balance is ingrained in our culture by design. Trust and accountability make it work.
• Donation matching. Give back? Give more! We match qualifying charitable donations annually.
• Tuition assistance. Want to level up your career? We love to hear it! Receive annual support for qualified programs.
• Lifestyle benefit. An annual benefit to spend on yourself. Use it on travel, wellness, or whatever suits you.
• Travel perks. We believe that travel is employee development, so we provide discounts and more.
• Employee assistance program. We’re here for you with resources and programs to help you through life’s challenges.
• Health benefits. We offer great coverage and competitive premiums.
• Generous referral scheme. Help us grow and be rewarded with generous awards for referring successful candidates.

We exist to create value for our customer, the traveler. We enable our suppliers and partners to unlock this value. Their collective behaviors and insights are what drives us.

Execution is our edge

We act fast, experiment, learn from failure, iterate, and improve the solutions of tomorrow across every aspect of our business. Our execution is agile, data-driven, prioritised, and built to scale. We assume no problem is someone else’s problem and finish what can be done today, knowing tomorrow will bring fresh challenges.

We succeed together

The best outcomes are driven by empathic, humble, and diverse subject matter experts working toward shared goals. We collaborate relentlessly, challenge assumptions, give actionable feedback, and set each other up for success through empowered teams with a clear charter. We transparently take ownership of our growth, individually and as a team. We celebrate the quality of our effort, our learnings, and our collective achievements.

We strive to create an accessible and inclusive experience for all candidates. If you need a reasonable accommodation during the application or the recruiting process, please make sure to reach out to your individual recruiter or our team at [e-mail].

If you have any additional questions about careers at Tripadvisor you can email us at [e-mail]. We have all the answers!