Principal Software Development Engineer

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. Note: This description has been reformatted for accessibility and clarity. The language remains as provided. Overview 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. Introduction to the Team: Our Technology Team partners with teams across Expedia Group 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. At Expedia Group Fraud & Risk (EFR), we are the guardians of marketplace trust. We protect EG from financial loss and brand damage, securing every channel for our customers, partners, suppliers, and employees. Our world class engineering and machine learning turn massive, noisy signals into real time decisions that minimize risk while keeping traveler friction low. What makes this work unique: in travel, risk doesn’t stop at checkout, it spans the entire journey. The global ecosystem is vast and fragmented, control points are scarce, and every leg introduces new unknowns. Our mission is bold: deliver a fully trusted journey from purchase to safe return home. That’s hard and exactly why science and technology matter most. If you’re energized by complex, high impact problems with no obvious answers, and want to shape the future of risk with AI on a global scale, join us. Let’s redefine how the world travels, safely, confidently, and at speed. Responsibilities Lead the architecture and delivery of real-time, AI-powered fraud and abuse defenses on a global scale. You will design cloud-native decisioning and automated remediation systems, simplify our platform, and align cross-functional teams to measurable outcomes. Own end-to-end architecture for low-latency risk decisioning (signals + rules + models) and automated remediation Build, deploy, and operate ML in production; partner closely with DS/ML on features, experimentation, and monitoring Simplify and modernize the platform (streaming/data pipelines, microservices, CI/CD, configuration-driven controls) to speed safe iteration Drive build-vs-buy evaluations and benchmark vendors against in-house solutions for performance, cost, and risk posture Establish clear SLOs, observability, and safety/rollback mechanisms; ensure security, privacy, and compliance are built in Mentor senior engineers and align Product, Ops, Security, and Compliance on roadmap and outcomes Communicate clearly with executives and engineering: distill strategy, make tradeoffs explicit, and document decisions. Minimum Qualifications 10+ years of software engineering, including 4+ years leading architecture for real-time, high-scale systems Proven experience building and operating fraud/risk systems in production (e.g., booking, payments/chargebacks, ATO, content/supplier integrity), with measurable impact on losses, false positives, and manual effort Production ML experience (supervised/anomaly detection, feature pipelines, online inference, monitoring/retraining); ability to ship with DS/ML partners Cloud-native engineering at scale (AWS, GCP, or Azure): event-driven services, data/stream processing, observability, cost and reliability best practices Strong coding skills in one or more of Java/Scala/Go/Python; microservices, APIs, and infrastructure-as-code Security, privacy, and regulatory fundamentals for sensitive data and risk decisioning Experience with executive communication: can brief executives, translate strategy into actionable engineering plans, and align teams Preferred Qualifications LLM/agentic techniques applied to fraud (e.g., investigation assist, pattern discovery, automated playbooks) and retrieval over enterprise data Graph/sequence modeling or entity resolution at scale; device and behavioral signals Track record reducing manual operations via automation and platform simplification Hands-on with experimentation platforms and real-time rules/model simulation/back testing Deep cloud cost/performance tuning and capacity planning Marketplace, travel, or e-commerce experience The total cash range for this position in Seattle is $231,000.00 to $323,500.00. Employees in this role have the potential to increase their pay up to $369,500.00, 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 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™. © 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. #J-18808-Ljbffr Expedia , Inc.