Staff Network Engineer (Fulfillment and Logistics Network Engineering)

Company Introduction We exist to wow our customers. We know we’re doing the right thing when we hear our customers say, “How did I 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 since our inception. We are all entrepreneurs 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.   Role Overview The Global Operations Tech (GOT) organization is responsible for the systems that enable Coupang to reliably deliver to customers within hours of orders being placed. GOT is on a mission to innovate logistics by building an efficient delivery network at breakthrough scale and speeds. As a Senior Staff Backend Engineer in GOT, you will leverage advanced algorithms to improve Coupang’s customer experience by ensuring ultra-fast deliveries are on time even during the busiest times of the year. We are looking for a Scientist that can drive the direction of technology across multiple teams, leverage deep industry knowledge and use statistical and machine learning techniques to bring value to customers. The ideal candidates are pragmatic, resourceful, and embrace challenges that are seemingly impossible. The ideal candidates also have rich industry experience and a track record of delivering highly impactful projects.   What You Will Do * Lead and drive architecture design of Fulfillment Technologies for scale, future extensibility, and reliability * Envision and drive alignment with stakeholders of the appropriate roadmap and future direction of technology for Global Operations Technology org. * Navigate and alleviate technical obstacles and blockers at the organizational level * Decompose complex problems into simple, straightforward solutions, providing mechanisms for the teams to prioritize ruthlessly and “move with urgency.” * Write code when necessary to lead by example and help with high-priority projects * Proactively identify opportunities in both business and technology * Review, advise, and carry out the adoption of new technology (both open-source and commercial) that are useful in achieving business objectives * Recruit and develop world-class engineering talent * Drive development of automation and robotics initiatives   Basic Qualifications * 15+ years of experience in developing and operating backend services and web applications * Solid track record of delivering large and complex systems with significant business impact * Experience of designing and developing large-scale distributed systems and architectures * Broad and deep understanding of key technologies in storage, data processing, and serving * Capable of object-oriented design and development * Strong familiarity developing with Java and the Spring Framework * Service development and operational experience in an AWS environment * Experience driving improvements in code quality   Recruitment Process and Others Recruitment Process * Application Review - 1st Interview - 2nd Interview - Offer * The exact nature of the recruitment process may vary according to the specific job and may be changed due to scheduling or other circumstances. * Interview schedules and the results will be informed to the applicant via the e-mail address submitted at the application stage. Details to Consider * This job posting may be closed prior to the stated end date for application if all openings are filled. * Coupang has the right to rescind an offer of employment if a candidate is found to have submitted false information as part of the application process. * Those eligible for employment protection (recipients of veteran’s benefits, the disabled, etc.) may receive preferential treatment for employment in accordance with applicable laws. * Job titles and responsibilities may be subject to change depending on the candidate’s overall experience, etc. This will be communicated to the candidate at the appropriate time before the offer. * Hiring may be restricted in case the legal qualifications required for hiring and work performance is not met. * This is a full-time regular position and includes 12 weeks of probation period; provided, however, the probationary period may be either skipped, shortened or extended if necessary for business purposes Privacy Notice * Your personal information will be collected and managed by Coupang as stated in the Application Privacy Notice located below. * https://privacy.coupang.com/en/land/jobs/ Document Return Policy 1. This notification is given pursuant to Article 11 (6) of the Fair Hiring Procedure Act. 2. A job applicant, who has applied but not been finally selected for a position at Coupang (the “Company”), may request the Company to return his/her hiring documents submitted pursuant to the Fair Hiring Procedure Act. However, this will not apply where the hiring documents were submitted via the website of the Company or e-mail, or where the job applicant submitted those documents voluntarily without a request from the Company. In addition, if the hiring documents were destroyed due to a natural disaster or any other reasons not attributable to the Company, such documents will be deemed to have been returned to the job applicant. 3. A job applicant who wishes to request the return of his/her hiring documents pursuant to the main sentence of paragraph 2 above should fill out a “Request for Return of Hiring Documents” [Annex Form No. 3 in the Enforcement Rule of the Fair Hiring Procedure Act] and submit It by email (recruitingops@coupang.com). In such case, within fourteen (14) days from the date of identifying the receipt of the request, the Company will send the hiring documents to the job applicant’s designated address via registered mail. Please be informed that the job applicant is required to pay the postage on the registered mail. 4. In preparation for a job applicant’s request for the return of hiring documents pursuant to the main sentence of paragraph 2 above, the Company shall retain the original hiring documents submitted by the job applicant for 180 days from the completion of the recruiting process. If no request is made until the end of this period, all his/her hiring documents will be destroyed immediately in accordance with the Personal Information Protection Act. 5. The above paragraphs 1 - 4 shall only apply when the labor-related laws of Korea govern the application. They are otherwise not applicable.

Company Introduction   We exist to wow our customers. We know we’re doing the right thing when we hear our customers say, “How did I ever live without Coupang?” Born out of an obsession to make shopping, eating, and living easier than ever, we’re collectively disrupting the multi-billion-dollar e-commerce industry from the ground up. We are one of the fastest-growing e-commerce companies that established an unparalleled reputation for being a dominant 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 since our inception. We are all entrepreneurs 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 trade-offs. Join Coupang now to create an epic experience in this always-on, high-tech, and hyper-connected world.     Role Overview Fulfilment Optimization (FO) owns the systems that decide how every Coupang order is planned, distributed, and fulfilled. Our Tier-1 services sit on the critical path of Coupang's ecommerce order flow — processing every order in real time across Korea and Taiwan. We operate multiple interconnected platform components: -Business Engine — Core order planning and distribution orchestrator (Kotlin/Spring Boot). Runs 5 distinct pipelines (Domestic, Cross-Market, 3PL, PDD, Replan) using a hexagonal architecture with pluggable processors, pruners, and manifest-based orchestration. -Planner Solver — Mixed-Integer Programming (MIP) optimization engine (Python/CPLEX) that minimizes total fulfilment cost across inventory, capacity, network, and delivery-promise constraints with sub-second latency requirements. -Network Manager — Manages fulfilment network topology, transportation cost, FC capacity, middle-mile logistics, and cross-FC consolidation (CFCC) across 90+ REST/gRPC endpoints. -FO Inventory — Real-time inventory availability, allocation, SKU management, and event-driven sync across multiple upstream sources (Kafka, Cassandra, Elasticsearch, Redis). -WMS Fulfilment — Order distribution, inventory allocation, fulfilment centre orchestration, shipment, delivery, and outbound management (Java/Spring, 138+ domain subpackages, Drools rules engine). -Online Simulation — Real-time simulation platform for testing planning changes against production-like order streams. -FO Workflows — Temporal-based workflow orchestration for long-running fulfilment processes. The Role We are looking for a Senior Staff Engineer who can operate across deep implementation and broad architecture. You will set the technical direction for Tier-1 fulfilment systems, write and review production code, design systems that scale under heavy ecommerce traffic, and raise the engineering bar across the organization. The engineer in this role will directly influence how millions of orders are fulfilled every day. Every architectural decision — solver latency, pruning strategy, network cost calculation, inventory allocation algorithm impacts customer delivery promise, fulfilment cost, and operational efficiency across Coupang's entire ecommerce platform in Korea and Taiwan. This is a rare opportunity to work at the intersection of large-scale distributed systems, real-time optimization, and ecommerce fulfilment — with direct, measurable business impact. What You Will Do  -Design and build scalable, reliable Tier-1 services for order planning, fulfilment optimization, inventory allocation, and network cost management — systems that process every Coupang order in real time. -Own architecture across distributed systems involving gRPC service meshes, Kafka event pipelines, CPLEX optimization solvers, multi-layer caching (Redis, S3-backed Loadable Stores), and multi-region deployments. -Write production code in Kotlin and Java and set the bar for correctness, performance, and operational safety across the team. -Lead design and code reviews — identify correctness issues, scalability risks, and operational gaps in systems handling latency-sensitive order flows (sub-second solver deadlines, P99 monitoring with 3-5s alert thresholds). -Drive reliability for mission-critical services — circuit breakers, graceful degradation (hard/soft pruners with fallback), observability, and incident prevention. -Partner with Product, Data Science, and Operations to translate fulfilment optimization goals into technical execution — PDD rationalization, CFCC (Cross-FC Consolidation), CFlow transport planning, inventory group management, and solver model improvements. -Mentor engineers and create durable technical mechanisms (pipeline patterns, adapter abstractions, feature flag discipline) that scale beyond individual projects   Basic Qualifications -Proven experience designing and operating high-scale distributed systems with strict latency and reliability requirements -Excellent hands-on coding ability in Kotlin or Java (backend systems at scale) -Deep understanding of system design — API design, concurrency, data modelling, caching strategies, messaging, service-to-service communication (gRPC, REST) -Strong code review skills — ability to identify subtle correctness, performance, and reliability issues in complex codebases -Experience with production-grade systems handling high QPS, large data volumes, or Tier-1 SLAs -Experience with event-driven architectures using Kafka at scale -Experience with multi-region systems — region-specific routing, data isolation, cross-border fulfilment -Experience with resilience engineering — circuit breakers, retry strategies, load testing, capacity planning, graceful degradation patterns -Track record of technical leadership — setting architecture direction, driving cross-team alignment, mentoring senior engineers   Preferred Qualifications -Experience in ecommerce, fulfilment, supply chain, logistics, inventory, order management, or planning systems -Experience with optimization systems — solvers (CPLEX, OR-Tools), decision engines, constraint programming, or data-science-integrated production systems -Experience with Agentic AI tools for development and code review — using AI-assisted coding agents (e.g., Cursor, Copilot, Devin, Claude Code) to accelerate development velocity, improve code review quality, and automate repetitive engineering tasks -Experience with Spec-Driven Development — defining system behaviour through specifications (OpenAPI/Swagger, Protocol Buffers, API-first design, contract-first development) before implementation, ensuring well-defined contracts between services   Type of work model * Hybrid Details to consider  * Those eligible for employment protection (recipients of veteran’s benefits, the disabled, etc.) may receive preferential treatment for employment in accordance with applicable laws.    Privacy Notice * Your personal information will be collected and managed by Coupang as stated in the Application Privacy Notice located below. https://privacy.coupang.com/en/land/jobs/