Principal Software Development Engineer

At Expedia Group, we help travelers explore the world, one journey at a time. As a global travel company powered by passionate people, trusted partnerships, and leading technology, we connect travelers, partners, and advertisers through our consumer brands, B2B network, and travel advertising business. Here, you'll do meaningful work that helps millions of people discover, book, and experience travel with more ease, confidence, and joy. Our five Behaviors-Traveler First, Think Big, Operate with Excellence, Ownership Mindset, and Succeed Together-help foster a supportive environment where people can grow their careers and have the flexibility, benefits, and support to do their best work. Join us and build for travelers everywhere. Introduction to team: the engineering organization responsible for Reservations across two of Expedia Group's largest lines of business: Conventional Lodging (hotels) and Vacation Rentals (Vrbo). This platform ensures that the booking is completed across all systems starting from the moment a traveller clicks "book" till the moment a supplier, a hotel property or a vacation rental host, actually confirms that room or home. It is the system of record and execution for every reservation created, retrieved, changed, cancelled, and reconciled across every EG brand and every point of sale, globally. The scale of these platforms is substantially high since Conventional Lodging alone represents a large majority of Expedia's transaction volume, processing bookings across local inventory, third-party inventory, and GDS supply. Vacation Rentals adds a second, structurally distinct booking model, whole-property rentals with owner/property-manager supply, dynamic quote-and-hold flows, and its own settlement and payout mechanics. Across both businesses, this organization owns dozens of production services spanning booking orchestration, price/availability validation, fulfilment, cancellation, change management, settlement, and event publishing to finance and analytics.   Typical technologies include Java/Kotlin, Spring, REST/gRPC, AWS, Datadog and Splunk. Platform capabilities you will own and continue to raise the bar on: Scalability — supporting booking, retrieve, and post-booking traffic that scales across markets, brands, and business models without re-architecting for every new use case. High-performance — the team is actively driving end-to-end booking latency down, because every additional second at checkout measurably costs conversion and revenue. High throughput — the platform must absorb booking, price-check, and inventory-adjustment traffic at production scale continuously, including peak demand events, without degrading the traveller experience. Resiliency — this is a highly compliant and audited revenue-critical system, designed with redundancy, safe rollout mechanisms, and recovery paths, because a failed booking is a failed sale. In this role, you will: Define and evolve technical direction for complex products, services, and domains, delivering scalable solutions that support business and customer outcomes Lead architecture and system design, including low-level design, API design, data modelling, and evaluation of technical trade-offs across interconnected systems Drive engineering execution across multiple services or a broad technical domain, aligning teams on priorities, delivery approaches, and sustainable technical practices Apply deep technical expertise to solve ambiguous, high-impact problems while remaining effective across multiple engineering domains and technology stacks Establish operationally excellent solutions through practices that strengthen reliability, observability, performance, security, maintainability, and continuous improvement Safely integrate and operate AI/ML-enabled solutions that improve outcomes, applying familiarity with AI-driven systems, tools, workflows, and AI/ML concepts to real-world products Minimum Qualifications: Bachelor’s degree in