Senior Machine Learning Scientist

You will need to login before you can apply for a job. Employer Expedia Group Location San Jose, California, United States Salary USD 187,000.00 - 261,500.00 ;USD 299,000.00 ;USD 173,000.00 - 242,500.00 ;USD 277,000.00 Closing date 5 May 2026 Why Join Us? 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. 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 Introduction to the Team: Expedia Technology teams partner with our Product teams to create innovative products, services, and tools to deliver high-quality experiences for travelers, partners, and our employees. A singular technology platform powered by data and machine learning provides secure, differentiated, and personalized experiences that drive loyalty and traveler satisfaction. The Traveler Discovery & Planning team at Expedia is at the forefront of innovation in AI-driven agentic systems. We're dedicated to enhancing customer experiences, increasing engagement, and strengthening traveler relationships through cutting-edge machine learning solutions. Our work directly impacts millions of travelers worldwide, shaping their journey from dreaming to booking and beyond. Join a team that is focused on Agentic Experiences revolutionizing traveler experiences through autonomous, intelligent agent systems. From building cutting-edge conversational AI that anticipates traveler needs to developing proactive solutions for personalized trip planning, your work will shape the future of travel assistance and directly impact millions of users worldwide. This is a rare opportunity to build foundational systems in a high-impact domain, backed by Expedia’s AI-first vision. In this role, you will: Design, build, and evaluate multi-step agentic AI systems, including autonomous agents capable of planning, tool use, memory management, and multi-agent collaboration Research and implement state-of-the-art techniques in agentic architectures, such as ReAct, reflection loops, chain-of-thought prompting, and tool-augmented reasoning Develop and maintain agent orchestration frameworks, defining how agents decompose tasks, delegate to sub-agents, and handle failure and recovery Integrate large language models (LLMs) with external tools, APIs, databases, and code execution environments to enable real-world task completion Define and own evaluation frameworks for agentic systems, measuring task success, reliability, latency, cost, and safety across diverse benchmarks and production scenarios Collaborate closely with product, engineering, and research teams to translate business requirements into agentic system designs and deliver production-grade solutions Identify and mitigate risks specific to agentic systems, including prompt injection, unintended actions, hallucination in long-horizon tasks, and unsafe tool use Stay current with the rapidly evolving agentic AI landscape, synthesizing academic research and industry developments to inform the team's technical direction Mentor junior ML engineers and scientists, providing technical guidance on agentic design patterns, LLM best practices, and experimentation methodology Minimum Qualifications: 8+ years of related industry experience Demonstrated experience designing and deploying agentic or multi-step AI systems (e.g., ReAct, tool‑calling agents, multi‑agent pipelines) in production or research settings Strong proficiency in Python and ML frameworks (PyTorch, TensorFlow, or JAX); experience with LLM APIs and orchestration libraries (e.g., LangChain, LlamaIndex, or similar) Experience integrating LLMs with external tools, APIs, and structured data sources for real‑world task completion Solid understanding of prompt engineering techniques including chain‑of‑thought, few‑shot prompting, and structured output generation Experience defining and running evaluation frameworks for ML systems, including offline benchmarking and production monitoring Preferred Qualifications: PhD, MS, or BS in Computer Science, Machine Learning, Statistics, Engineering, or a related field; or equivalent professional experience Experience in the travel or e‑commerce industry Publications in top‑tier ML conferences or journals Patented Inventions, pending and issued Contributions to open‑source ML projects Experience taking models from prototype to production in collaboration with Machine Learning Engineering teams The total cash range for this position in San Jose is $187,000.00 to $261,500.00. Employees in this role have the potential to increase their pay up to $299,000.00, which is the top of the range, based on ongoing, demonstrated, and sustained performance in the role. The total cash range for this position in Seattle is $173,000.00 to $242,500.00. Employees in this role have the potential to increase their pay up to $277,000.00, which is the top of the range, based on ongoing, demonstrated, and sustained performance in the role. 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. Expedia Group’s family of brands includes: Brand Expediareg;, Hotels.comreg;, Expediareg; Partner Solutions, Vrboreg;, trivagoreg;, Orbitzreg;, Travelocityreg;, Hotwirereg;, Wotifreg;, ebookersreg;, CheapTicketsreg;, Expedia Group™ Media Solutions, Expedia Local Expertreg;, CarRentals.com™, and Expedia Cruises™. © 2024 Expedia, Inc. All rights reserved. Trademarks and logos are the property of their respective owners. CST: 2029030-50 Employment opportunities and job offers at Expedia Group will always come from Expedia Group’s Talent Acquisition and hiring teams. Never provide sensitive, personal information to someone unless you’re confident who the recipient is. Expedia Group does not extend job offers via email or any other messaging tools to individuals with whom we have not made prior contact. Our email domain is @expediagroup.com. The official website to find and apply for job openings at Expedia Group is careers.expediagroup.com/jobs. Expedia is committed to creating an inclusive work environment with a diverse workforce. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. This employer participates in E‑Verify. The employer will provide the Social Security Administration (SSA) and, if necessary, the Department of Homeland Security (DHS) with information from each new employee’s I‑9 to confirm work authorization. Create a job alert and receive personalised job recommendations straight to your inbox. #J-18808-Ljbffr