Senior Backend Engineer - MTS 1

eBay • Toronto, ON

10d

About The Position

At eBay, we're more than a global ecommerce leader — we’re changing the way the world shops and sells. Our platform empowers millions of buyers and sellers in more than 190 markets around the world. We’re committed to pushing boundaries and leaving our mark as we reinvent the future of ecommerce for enthusiasts. Our customers are our compass, authenticity thrives, bold ideas are welcome, and everyone can bring their unique selves to work — every day. We're in this together, sustaining the future of our customers, our company, and our planet. Join a team of passionate thinkers, innovators, and dreamers — and help us connect people and build communities to create economic opportunity for all. About the Team We are reinventing advertising at eBay! We’re creating innovative ad-tech solutions to optimize the ad monetization and experience on eBay. Our goal is to create a valuable experience for both buyers and sellers, while also driving performance through Ads. To that end, we are innovating rapidly in the ad-tech space and there is no shortage of new challenges for motivated individuals. As a Senior Backend Engineer, you will work closely with designers, product managers and other engineers (frontend, backend, native, machine learning, quality) to redefine the advertising space for eBay and beyond.

Requirements

• BS/BA in Computer Science or related field with 5+ years of experience, or MS with 3+ years Backend
• Strong experience in Java (17+) and building services with Spring Boot or similar frameworks
• Experience building scalable backend systems and RESTful APIs in distributed environments
• Experience with event-driven architectures and message queues (Kafka, RabbitMQ, or similar)
• Experience with relational (Oracle/Postgres/MySQL) and/or NoSQL (Cassandra/MongoDB) databases, including schema design and query optimization
• Strong system design experience for distributed, high-traffic applications (able to lead a 45-min system design interview)
• Ability to reason about system design trade-offs (e.g., consistency vs availability, sync vs async)
• Solid computer science fundamentals (data structures, algorithms)
• Experience with CI/CD tools (Jenkins, GitHub Actions)
• Strong ownership mindset with ability to drive work end-to-end in a collaborative environment
• Ability to build LLM workflows or AI-driven automation

Nice To Haves

• Scala
• Experience with Node.js and modern backend frameworks (Express, NestJS, Fastify)
• Exposure to GraphQL and experience in building Federated GraphQL APIs is highly desirable.
• Familiarity with columnar databases
• Experience with AI-assisted development tools (e.g., Copilot, Cursor, Claude Code)
• Contributions to open source, GitHub projects, or side projects

Responsibilities

• Design new experiences for eBay sellers and advertisers to promote their products, manage their advertising campaigns, and run their businesses
• Develop highly available, scalable RESTful APIs and event-driven systems processing billions of ad-serving and bidding events with strict latency and reliability requirements
• Develop systems using Java/Scala, Spring Boot, and Node.js across our microservices architecture
• Implement well-designed backend services following established architectural patterns, and contribute to design documents and technical reviews with peers and senior engineers.
• Understand and apply trade-offs in system design (consistency, availability, latency, cost) within your service area
• Leverage AI-assisted development tools (e.g., GitHub Copilot, Claude Code) throughout the development lifecycle for coding, debugging, testing, and code review to increase engineering velocity
• Contribute to AI-powered advertising features by collaborating with ML engineers on LLM integrations, recommendation systems, and intelligent campaign optimization
• Evaluate and adopt new technologies—including AI-assisted tools—to improve system quality and engineering velocity.
• Operate within our internal open source community where we share a variety of projects and codebases
• Develop, test, and deploy services through automated CI/CD pipelines with a focus on reliability and observability
• Work effectively within a fast-paced, Agile team, adapting to evolving priorities and delivering iterative value to customers
• Contribute to technical conversations and debates, and decide upon approaches and tools to utilize

Benefits

• RRSP eligibility
• various paid time off benefits, such as PTO and parental leave
• target bonus
• restricted stock units
• full range of medical, financial, and/or other benefits

What This Job Offers

• Job Type: Full-time
• Career Level: Senior