Senior Fastapi Developer Jobs in Wheaton, IL (NOW HIRING)

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 Technologyteamspartner 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 Senior Software Developer role is part of the GenAI Platform team. The GenAI Platform team builds and operates Expedia Group's shared generative AI platform - tooling, services, and guardrails - that enable product and ML teams to safely experiment with, deploy, and scale GenAI-powered experiences across our brands. You will lead the design, delivery, and evolution of scalable GenAI services and multi-agent infrastructure that power secure, observable GenAI capabilities across Expedia Group. By shaping multi-agent platform architecture, codifying guardrails and best practices, and partnering closely with product and domain engineering teams, you will accelerate how internal teams build, integrate, and safely operate AI-enabled experiences for travelers and partners at global scale.

In this role, you will:

• Design, build, and operate Python/FastAPI backend services and APIs that power GenAI Platform capabilities such as RAG managers, data planes, and vector store services, with strong focus on system design, API design, and data modeling.

• Implement clean, maintainable, and well-tested code using modern engineering practices including code reviews, CI/CD pipelines, automated testing, monitoring, alerting, and participating in on-call rotations where applicable.

• Integrate platform services with internal and external LLM providers, Elasticsearch-based vector stores, and Aurora PostgreSQL as part of scalable, reliable RAG and retrieval workflows across multiple domains.

• Contribute to and evolve GenAI platform guardrails and safety features (authentication, API key management, workload-to-workload authentication, evaluation and observability hooks) so AI-enabled applications are secure, responsible, observable, cost-aware, and safely integrate and operate AI/MLenabled solutions that improve outcomes.

• Partner closely with staff and principal engineers, product managers, applied scientists, and other engineering teams to refine requirements, shape platform architecture (including multi-tenant vector stores and workflow integrations), and deliver incremental, production-ready value.

• Create and maintain clear technical documentation (design docs, runbooks, implementation guides, and how-tos) that enables other teams to successfully adopt, extend, and build on GenAI Platform services and paved roads.

Minimum Qualifications:

• Bachelor's degree in Computer Science or a related technical field; or Equivalent related professional experience.

• 8+ years of relevant professional experience, including building and operating backend services and APIs with end-to-end ownership from design through deployment and ongoing operational support.

• Proven proficiency in Python and experience developing production-grade web services using FastAPI or similar modern frameworks (such as Flask, Django, or other async service frameworks), with solid understanding of system design, API design, and data modeling.

• Experience building and running backend APIs in public or hybrid cloud environments, with hands-on exposure to core cloud services (AWS preferred) and at least one data store technology (relational, NoSQL, or search), such as Aurora PostgreSQL or Elasticsearch.

• Familiarity with AI-driven systems, tools, or workflows and applying AI/ML concepts to real world products, including exposure to LLM-powered capabilities, embeddings, or RAG patterns, or demonstrated ability to ramp up quickly using internal GenAI Platform tools and documentation.

Preferred Qualifications:

• Deep experience building and operating Python-based backend APIs at scale on AWS or similar cloud providers, including performance tuning, resilience patterns, and advanced API and data modeling for high-traffic or multi-tenant services.

• Hands-on experience with RAG and vector store tooling (for example, LangChain, LlamaIndex, LangGraph) and evaluation or observability frameworks (such as LangSmith or Langfuse), including safely integrating and operating AI/MLenabled solutions that improve outcomes.

• Experience integrating and optimizing LLM-powered systems end to end, including prompt and retrieval design, embeddings management, Elasticsearch vector search, Aurora PostgreSQL schemas, and platform-level guardrails such as auth, quota, and evaluation hooks.

• Background building internal platforms, SDKs, or shared services adopted by multiple product teams, including clear documentation, paved road patterns, and close collaboration with cross-functional partners (product management, applied science, and engineering).

• Experience designing or implementing workflow and agent orchestration-based solutions (for example, using n8n, Flowise, or similar) to build multi-tool or multi-agent GenAI applications, and familiarity with AI-driven platform architectures and safety-by-design practices.

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 perks

Expedia 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 https://careers.expediggroup.com/life.

Accommodation requests

Expedia 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 https://expedia.service-now.com/askeg?id=job_accommodation.

About Expedia Group

Expedia 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 notice

Employment 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 https://careers.expediagroup.com/jobs/.

Equal Opportunity

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, 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.