Software Development Engineer III - C++

Expedia Expedia · Hospitality · Seattle, WA

Software Development Engineer III role focused on building and optimizing high-performance C++ systems for Expedia Group's core technology platform. Responsibilities include system design, implementation, code reviews, collaboration with product teams, and mentoring. The role involves working with AI/ML-enabled solutions but is not primarily an AI/ML development role.

What you'd actually do

  1. Own design and implementation of critical services and components, with a focus on clean API design, robust data modeling, and reliable system behavior.
  2. Lead and contribute to system design, including low‑level design decisions, to ensure services are scalable, observable, and maintainable.
  3. Implement high‑quality, well‑tested C++ code; conduct and drive code reviews; and help advance engineering standards, tooling, and best practices across the team.
  4. Collaborate closely with product, design, and partner engineering teams to deliver features end‑to‑end, balancing technical quality with delivery timelines.
  5. Safely integrate and operate AI/ML‑enabled solutions that improve outcomes, leveraging AI‑driven systems, tools, or workflows where appropriate.

Skills

Required

  • Bachelor’s degree in Computer Science, Computer Engineering, or related technical field, or equivalent related professional experience.
  • 5+ years of relevant professional software engineering experience (or equivalent depth of experience).
  • Demonstrated professional experience owning services or components within a broader production system.
  • Strong proficiency in C++ and its ecosystem, including hands‑on experience with API design, data modeling, and system design (including low‑level design).
  • Experience building, testing, deploying, and operating backend or full‑stack services in production environments, including participation in on‑call or incident response rotations as appropriate.
  • Solid foundation in algorithms, data structures, and object‑oriented design.

Nice to have

  • Experience building high-performance, production-grade C++ systems with a focus on performance optimization, memory efficiency, concurrency, and reliability at scale.
  • Strong background in systems design and API development, including designing maintainable interfaces, data models, and evolving existing architectures in complex distributed environments.
  • Demonstrated experience improving engineering quality through: Refactoring legacy code, Optimizing performance-critical paths, Strengthening observability, Advancing testing and operational practices.
  • Practical experience using telemetry and diagnostics (metrics, logs, tracing, profiling, experimentation) to analyze and improve system behavior.
  • Exposure to integrating intelligent or AI‑enabled capabilities into backend systems (for example, inference APIs, personalization features, or AI‑assisted engineering workflows) and interest in leveraging emerging technologies to enhance system performance and developer productivity.
  • Experience mentoring other engineers and contributing to hiring, onboarding, and raising the technical bar for the team.

What the JD emphasized

  • high-performance C++ systems
  • performance optimization
  • memory efficiency
  • concurrency
  • reliability at scale
  • systems design
  • API development
  • evolving existing architectures in complex distributed environments
  • improving engineering quality
  • Refactoring legacy code
  • Optimizing performance-critical paths
  • Strengthening observability
  • Advancing testing and operational practices
  • telemetry and diagnostics
  • analyze and improve system behavior