Senior Software Development Engineer, Advertising Technology (Chicago)

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 the team Expedia Group Advertising builds the platforms and experiences that connect advertisers with millions of travelers across the globe. Our mission is to help partners reach the right traveler with the right message at the right time through intuitive advertiser experiences, high-performance ad delivery systems, and intelligent AI-powered optimization. We are growing our Advertiser Experience engineering team and are looking for a talented, product-minded Senior Software Development Engineer with deep experience building and operating production machine learning systems. This role is ideal for an engineer who combines strong software engineering fundamentals with hands-on ML engineering expertise and is passionate about bringing intelligent capabilities into customer-facing products at scale. You will help shape the next generation of our advertising marketplace by building scalable advertiser-facing platforms, backend services, and ML-powered capabilities that drive measurable business outcomes. Working at the intersection of distributed systems, machine learning, and product development, you will be responsible for productionizing and operating intelligent systems that power recommendations, ranking, forecasting, decision support, and generative AI experiences for advertisers. Success in this role requires the ability to design and build production-grade software, deploy and operate machine learning models and inference services at scale, and partner closely with ML engineers, applied scientists, and product teams to transform data and models into impactful advertiser experiences.In This Role, You WillLead the design, implementation, and evolution of backend APIs and distributed services that power high-quality advertiser experiences with strong performance, reliability, trust, and transparency.Own and evolve the architecture of core platform services supporting campaign management, optimization, and intelligent decisioning across Expedia Group’s advertising network.Build and operate production systems that integrate machine learning into advertiser workflows, including recommendations, smart defaults, ranking, prediction, forecasting, and AI-assisted decision support.Lead the application of LLMs and generative AI to improve campaign setup, streamline configuration workflows, and automate repetitive operational tasks at scale.Collaborate with software engineers and ML engineers or applied scientists to design and deliver batch and real-time systems for advertising use cases.Drive end-to-end delivery of complex, multi-quarter initiatives from technical design through production deployment, monitoring, and iterative improvement.Establish and uphold engineering best practices across software and ML-powered systems, including code quality, testing, observability, system reliability, and model/service monitoring.Design and operate scalable data and ML-enabled services, including feature pipelines, inference services, experimentation frameworks, and production monitoring for model and system health.Partner with product, UX, analytics, and business stakeholders to identify high-impact opportunities and translate them into scalable technical solutions.Contribute to cross-team initiatives that improve performance, scalability, and operational maturity of platform and AI-driven systems.Mentor engineers through design reviews, code reviews, and technical guidance, helping raise the bar for engineering quality and system design.Minimum QualificationsBachelor’s degree with 8+ years of experience, or Master’s degree with 6+ years of experience, in a related technical field; or equivalent professional experience.Strong experience designing and building scalable backend services and distributed systems in production.Strong programming experience in Python and at least one of Java, Kotlin, or similar backend languages.3+ years of hands-on experience building, deploying, and operating machine learning or AI-powered systems in production environments.Experience integrating ML models or AI capabilities (e.g., recommendations, ranking, prediction, or LLM-based features) into production software systems.Experience working with data and ML pipelines, including batch or streaming data processing and model inference workflows.Familiarity with cloud-native distributed systems and platforms such as AWS, Kubernetes, or equivalent.Experience collaborating with product and business partners to translate requirements into technical solutions.Proven ability to lead end-to-end technical design for complex systems and deliver them in production.Preferred QualificationsExperience building or operating LLM-based systems such as RAG pipelines, embeddings-based retrieval, or AI copilots.Experience with ML infrastructure components such as feature stores, model serving systems, or experimentation platforms.Experience with data processing frameworks such as Spark or similar large-scale processing tools.Experience with MLOps practices, including model versioning, CI/CD for ML systems, automated evaluation, monitoring, and retraining.Experience mentoring engineers and contributing to technical leadership within a team.Strong communication skills with the ability to explain technical tradeoffs to both technical and non-technical audiences.Experience in advertising, marketplaces, e-commerce, or travel domains.What Success Looks LikeYou build and evolve scalable advertiser platform services that are reliable, maintainable, and widely adopted by partner teams.You successfully bring ML and AI-powered capabilities into production that measurably improve advertiser outcomes and reduce operational complexity.You strengthen engineering excellence across system design, reliability, observability, and production readiness.You contribute to shaping how AI and ML are applied within advertiser-facing products while growing the technical capability of the team.Location:Please note that this role is only available in Chicago, IL, in alignment with our flexible work model, which requires employees to be in the office at least three days a week. We are unable to offer relocation assistance for this role.The total cash range for this position in Chicago is $171,500.00 to $240,000.00. Employees in this role have the potential to increase their pay up to $274,500.00, 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.Benefits and perksExpedia Group offers benefits and perks designed to support employees and their families, including medical, dental, and vision coverage, paid time off, an Employee Assistance Program, wellness and travel reimbursement, travel discounts, and International Airlines Travel Agent Network (IATAN) membership. Learn more about life at Expedia Group at .Accommodation requestsExpedia Group is committed to providing an inclusive and accessible recruiting experience. If you need an accommodation or adjustment due to a disability during the application or recruiting process, please submit a request at .About Expedia GroupExpedia Group includes three flagship consumer brands - Expedia, Hotels.com, and Vrbo - along with a leading B2B travel business and travel advertising offerings. Across our brands and business, we help travelers explore the world with confidence and ease.Important noticeEmployment opportunities and job offers at Expedia Group will always come from Expedia Group's Talent Acquisition and hiring teams. Never share sensitive personal information unless you are confident of the recipient. Expedia Group does not extend job offers via email or messaging tools to individuals with whom we have not made prior contact. Our email domain is @expediagroup.com. The official place to find and apply for roles is .Equal OpportunityExpedia 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, veteran status, or any other characteristic protected by law. 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.SummaryLocation: USA - Illinois - ChicagoType: Full time