Senior Machine Learning Scientist

Expedia Group brands power global travel for everyone everywhere. We design cutting-edge tech to make travel smoother and more memorable and we create groundbreaking solutions for our partners. Our diverse vibrant and welcoming community is essential in driving our success.

Why Join Us?

To shape the future of travel people must come first. Guided by our Values and Leadership Agreements we foster an open culture where everyone belongs differences are celebrated and know that when one of us wins we all win.

We provide a full benefits package including exciting travel perks generous time-off parental leave a flexible work model (with some pretty cool offices) and career development resources all to fuel our employees' passion for travel and ensure a rewarding career journey. We’re building a more open world. Join us.

Senior Machine Learning Scientist

The Senior Machine Learning Scientist is responsible for building and evaluating GenAI- and LLM-powered solutions and AI agents that improve post-booking customer experience including recommendations customer service and trip management. Owns end-to-end ML and GenAI projects—from problem framing and data preparation through model/agent design orchestration deployment and continuous evaluation. Applies deep expertise in applied ML Generative AI and rigorous experimentation to design robust evaluation frameworks (A/B tests offline metrics qualitative assessments) that ensure agents are safe effective and aligned with business goals. Partners closely with product engineering and operations while mentoring junior scientists and helping define best practices for AI agent development and evaluation.

Are you passionate about using machine learning to improve customer experience at scale? Would you like to work in the fast-paced competitive customer-focused and data-rich world of online travel? 

Our Machine Learning and Data Science team is growing. We are looking for a Senior Machine Learning Scientist to help tackle some of the most complex customer experience problems in the travel domain. You will develop state-of-the-art machine learning and AI solutions to power and enhance the customer experience across highly complex post‑booking recommendations customer service and trip management use cases. 

You will tackle substantial technical challenges from inference problems on long-tail traveler data to multi-objective optimization in a highly dynamic operationally complex customer service environment. Your passion for the craft of machine learning causal inference and Generative AI will unlock tangible growth for our business by exploiting rich datasets and building effective solutions for travelers and our partners. 

This is your opportunity to build core algorithms that help Expedia Group's Post Booking organization bring context and intelligence to every step of the traveler journey and redefine what service excellence in travel can be. We are looking for a hands-on senior scientist who can independently drive impactful projects mentor others and collaborate closely with partners to make travel more seamless for millions of customers and partners worldwide. 

In this role you will:

Design & Implement ML Solutions 

• Own the end-to-end ML lifecycle for medium-to-large projects: from problem framing and ideation through research prototyping deployment and post-launch monitoring. 

• Design robust scalable ML systems (batch and/or streaming) in partnership with engineering including data pipelines feature computation and model serving. 

• Translate ambiguous business problems into well-defined ML problems with clear success metrics and validation strategies. 

Applied Machine Learning & Data Science 

• Develop evaluate and iterate on supervised unsupervised and deep learning models for prediction recommendation and optimization. 

• Apply causal inference and experimental design (A/B testing) to accurately measure impact and guide decision-making. 

• Read and apply relevant academic and industry research to improve model architectures training strategies and evaluation methods. 

• Contribute to defining best practices for experimentation and modeling within the team; help raise the technical bar for ML development. 

Generative AI & Advanced Techniques 

• Build and iterate on models and applications leveraging GenAI / LLM technologies (e.g. OpenAI Hugging Face Anthropic Gemini) for customer support content generation and workflow automation. 

• Use prompting retrieval-augmented generation and tool/function-calling patterns to integrate LLMs into production systems. 

• Explore and prototype advanced ML techniques (e.g. reinforcement learning sequence modeling transformers) where they can provide clear business value. 

Statistics Experimentation & Model Design 

• Design end-to-end modeling approaches including data selection feature engineering algorithm choice training procedures and evaluation. 

• Apply statistical rigor in analyzing experiments and observational data; quantify uncertainty trade-offs and model risk. 

• Define and monitor offline and online metrics that faithfully reflect business goals (e.g. customer satisfaction cost-to-serve operational efficiency). 

Collaboration Communication & Visualization 

• Partner closely with product managers engineers analysts and operations to understand requirements define roadmaps and align on priorities. 

• Communicate complex technical concepts in a clear concise way to technical and non-technical stakeholders. 

• Build intuitive dashboards and visualizations to explain model behavior experiment results and business impact. 

Stakeholder & Project Management 

• Lead cross-functional projects involving multiple partners (e.g. product engineering operations) driving them from conception to measurable impact. 

• Manage project scope timelines and communication proactively surfacing risks and trade-offs. 

• Mentor junior scientists and engineers on modeling approaches experimentation and analytical problem solving. 

Experience & Qualifications:

Experience & Education 

• PhD in a quantitative field (e.g. Computer Science Statistics Mathematics Physics Economics Operations Research) and ~3+ years of industry experience; 
  or Master’s degree in a quantitative field with ~5+ years of relevant industry experience. 

• Proven track record of building and deploying ML models that meaningfully impact business metrics in a production environment. 

Functional & Technical Skills 

Applied ML & Statistics 

• Strong knowledge of machine learning theory and practice (e.g. supervised learning representation learning ranking/recommendation deep learning). 

• Solid grounding in statistics experimental design (A/B testing) and basic causal inference; comfortable designing and analyzing online experiments. 

• Able to design end-to-end ML solutions: frame the problem choose data sources select algorithms define evaluation strategies and iterate based on results. 

Engineering & Tooling 

• Strong programming skills in Python and its data/ML ecosystem (e.g. pandas scikit-learn PyTorch/TensorFlow PySpark) plus proficiency in SQL. 

• Experience working with cloud-based data/compute platforms and modern data/ML tooling (e.g. Spark Airflow feature stores model serving frameworks). 

• Follow software engineering best practices (version control code reviews testing documentation) and contribute to shared libraries and tooling. 

Generative AI & Advanced Methods 

• Hands-on experience using GenAI / LLM APIs (e.g. OpenAI Hugging Face Anthropic Gemini) in prototypes or production is highly desired. 

• Familiarity with concepts like prompt engineering retrieval-augmented generation function/tool calling and evaluation of LLM-based systems. 

• Experience with reinforcement learning bandits or other advanced ML techniques is a plus. 

Problem Solving & Communication 

• First-principles problem solver: able to decompose ambiguous problems identify key assumptions and design pragmatic iterative solutions. 

• Excellent written and verbal communication skills; able to tell a compelling story with data and models and influence decisions. 

• Collaborative and customer-obsessed with the ability to balance scientific rigor and engineering pragmatism in a product environment. 

Highly Desired Experience 

• Domain experience in customer service recommendations personalization or e-commerce applications. 

• Experience building ML systems for operational decision-making (e.g. contact routing triage capacity/effort prediction workflow optimization). 

• Experience mentoring other scientists or engineers and contributing to technical culture (e.g. brown bags tech talks documentation best practices). 

If you’re excited about building impactful ML and AI solutions that improve how millions of travelers are served every day we’d love to hear from you. 

Starting pay for this role will vary based on multiple factors including location available budget and an individual’s knowledge skills and experience. Pay ranges may be modified in the future.

Expedia Group is proud to offer a wide range of benefits to support employees and their families including medical/dental/vision paid time off and an Employee Assistance Program. To fuel each employee’s passion for travel we offer a wellness & travel reimbursement travel discounts and an International Airlines Travel Agent (IATAN) membership. View our full list of benefits.

Accommodation requests

If you need assistance with any part of the application or recruiting process due to a disability or other physical or mental health conditions please reach out to our Recruiting Accommodations Team through the Accommodation Request.

We are proud to be named as a Best Place to Work on Glassdoor in 2024 and be recognized for award-winning culture by organizations like Forbes TIME Disability:IN and others.

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What We Do

Expedia Group powers travel for everyone everywhere through our global platform. Driven by the core belief that travel is a force for good we help people experience the world in new ways and build lasting connections. We provide industry-leading technology solutions to fuel partner growth and success while facilitating memorable experiences for travelers. Expedia Group's family of brands includes: Brand Expedia® Hotels.com® Expedia® Partner Solutions Vrbo® trivago® Orbitz® Travelocity® Hotwire® Wotif® ebookers® CheapTickets® Expedia Group™ Media Solutions Expedia Local Expert® CarRentals.com™ and Expedia Cruises™.

Why Work With Us

As travelers and technologists we are passionate about making travel more seamless accessible and memorable. We embrace different perspectives celebrate new ideas and empower every Expedian to drive meaningful change. The experiences we create bridge divides and broaden horizons – helping create unforgettable memories through travel.

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