Sr. Software Engineer - Backend

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. The Team Join a newly formed engineering team at eBay focused on building Authentication as a Service , a platform designed to extend eBay's authentication capabilities to other marketplaces and partners. Today, eBay's Authenticity Guarantee program helps build trust in high-value transactions by authenticating eligible items before they reach buyers. We're expanding these capabilities beyond eBay, starting with Depop, and building a scalable, reusable platform that can support new authentication experiences across multiple marketplaces. This initiative involves re-architecting existing systems and building new cloud-native services from the ground up. You'll join a small, highly collaborative team with significant ownership over the architecture, infrastructure, and engineering foundations of this new platform. The Role We are looking for a Senior Software Engineer with strong backend development experience and hands-on expertise in cloud infrastructure and DevOps. This is a software engineering role first , combining the design and development of scalable backend services with direct ownership of cloud infrastructure, deployment automation, and production reliability. You'll help shape the architecture of a new platform, build distributed services, and establish the cloud infrastructure needed to support reliable, scalable authentication workflows. What You Will Accomplish • Design, develop, and operate scalable backend services, APIs, and distributed systems using technologies such as Java, Spring Boot, and REST. • Build and manage cloud infrastructure using Terraform, primarily on Google Cloud Platform (GCP). • Provision and operate cloud services, including Cloud Run, databases, load balancers, messaging systems, and related infrastructure. • Design event-driven and asynchronous architectures using technologies such as Google Pub/Sub, Kafka, or comparable messaging platforms. • Develop and improve CI/CD pipelines, deployment automation, monitoring, and observability to support reliable production operations. • Contribute to architectural decisions involving scalability, fault tolerance, security, performance, and cloud cost efficiency. • Own backend services throughout their lifecycle, from technical design and implementation through deployment, troubleshooting, and continuous improvement. What You Will Bring • 6+ years of professional software engineering experience, with a strong background in building production-grade backend applications. • Proficiency in Java or comparable backend languages such as Python, C#, or Go, with a willingness to develop in Java. • Experience designing and developing backend services, RESTful APIs, microservices, and distributed systems. • Hands-on experience provisioning and managing cloud infrastructure using Terraform or equivalent Infrastructure as Code practices. • Practical experience developing and operating applications on GCP or AWS, including cloud compute, databases, networking, and asynchronous messaging services. • Experience with CI/CD pipelines, containerized applicatio