Senior Staff Back-end Engineer (eCommerce Engineering)

We exist to wow our customers. We know we’re doing the right thing when we hear our customers say, “How did we ever live without Coupang?” Born out of an obsession to make shopping, eating, and living easier than ever, we are collectively disrupting the multi-billion-dollar commerce industry from the ground up and establishing an unparalleled reputation for being leading and reliable force in South Korean commerce.

We are proud to have the best of both worlds — a startup culture with the resources of a large global public company. This fuels us to continue our growth and launch new services at the speed we have been at since our inception. We are all entrepreneurial surrounded by opportunities to drive new initiatives and innovations. At our core, we are bold and ambitious people that like to get our hands dirty and make a hands-on impact. At Coupang, you will see yourself, your colleagues, your team, and the company grow every day.

Our mission to build the future of commerce is real. We push the boundaries of what’s possible to solve problems and break traditional tradeoffs. Join Coupang now to create an epic experience in this always-on, high-tech, and hyper-connected world.

Team Overview

The Service Engineering team builds, operates, and scales the core back-end platforms that power the most critical pages across Coupang's mobile apps and web — including Home, Search, Category, Detail Page, Cart, Checkout, and Order.

Our mission is to create a next-generation data-serving platform that is highly scalable, highly available, and robust, capable of handling millions of user requests globally. We serve as the backbone of the Coupang shopping experience, and our systems are expanding beyond the Korean market to global markets such as Taiwan.

 As a team, we focus on:

• Platform scalability — designing systems that reliably handle massive traffic at low latency across multiple regions
• Engineering excellence — maintaining best-in-class standards in code quality, architecture, testing, and operational excellence
• AI-driven effectiveness — leveraging AI and emerging technologies to improve engineering productivity, software quality, and delivery velocity
• Global expansion — building a platform architecture that generalizes across markets without sacrificing performance or reliability

Role Overview

We are looking for a Senior Staff Back-End Engineer to serve as the technical leader for the data-serving domain within Service Engineering. In this role, you will own the area-level technical strategy and roadmap, lead projects across multiple groups, and advise senior engineering and product leaders on strategic decisions. You will proactively identify and solve systemic technical problems spanning your area — navigating major risks, conflicting constraints, and non-technical complexity — while establishing outcome-based measurement to validate that AI and automation gains translate into real quality and cost-effectiveness. You will align technical and AI strategy with adjacent organizations, drive consensus on contentious topics, and guide the career growth of the most senior talent in your scope.

Basic Qualifications

• 10+ years of professional backend development experience (excluding internships)
• 7+ years of experience in Java/Kotlin/Spring-based service development and 3+ years in architecture leadership
• Proven experience designing and operating web-scale microservices; hands-on experience with AWS and Kubernetes
• Deep expertise in diagnosing mission-critical system failures, identifying root causes, and institutionalizing preventive measures
• Strong communication and leadership skills to align stakeholders and drive complex technical decisions across organizations

Preferred Qualifications

• Hands-on experience designing, building, and deploying highly-available distributed multi-tier services at global scale (multi-region, multi-datacenter)
• Experience with cloud computing on AWS at scale — cost optimization, multi-AZ/multi-region resilience, service quotas management
• Experience developing and operating services on Kubernetes environments at production scale
• Experience building or owning data pipelines with Spark, Cassandra, Kafka, and Airflow
• Track record of driving engineering excellence initiatives: reliability programs, performance optimization, tech debt reduction
• Experience authoring and socializing design documents or ADRs that influence engineering direction beyond own team

 AI & Harness Engineering Qualifications

• Demonstrated proficiency in AI-assisted software engineering — systematic use of AI tools (Copilot, Claude Code, Devin, Cursor) across planning, implementation, testing, review, and documentation
• Experience designing AI-augmented engineering workflows for the team — prompt engineering, context management, agent-driven automation — and integrating AI capabilities into team processes (automated code review, test generation, incident triage, documentation synthesis)
• Track record of measurable productivity gains through AI tool adoption (e.g., increased PR throughput, reduced cycle time, improved code quality metrics)
• Vision for evolving team engineering practices as AI capabilities advance — proactively identifying high-leverage opportunities in system design, operational excellence, and developer experience