Staff System Engineer

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 tradeoffs. Join Coupang now to create an epic experience in this always-on, high-tech, and hyper-connected world.  Role Overview As a Systems & Platform Engineer, you will design and develop responsive applications, scalable APIs, and domain-specific AI models while driving performance, reliability, and automation. You will leverage modern technologies across frontend, backend, cloud, and infrastructure domains to deliver innovative AI-powered enterprise solutions. What You Will Do Build and maintain modern, responsive, and high-performance agentic operations platform.
 Design, develop, and optimize small language models for domain-specific and enterprise applications. Fine-tune SLMs to improve accuracy, performance, and task-specific capabilities. Optimize models for low-latency inference and edge deployments. Develop inference pipelines and evaluate model performance across various environments. Monitor, benchmark, and improve model efficiency, accuracy, and scalability. Maintain documentation, experiment tracking, and model governance practices. Build scalable RESTful APIs and backend services Design and maintain relational/NoSQL databases Implement security, authentication, and authorization logic 
Ensure high availability, fault tolerance, and robustness of server-side applications Integrate third-party APIs and services securely and efficiently Basic Qualifications Bachelor’s degree or Master's degree with 7+ years of total experience Strong Python, React.js, NodeJS, NextJS, skills with component lifecycle, hooks, and state management
HTML5, CSS3, JavaScript (ES6+), and modern frameworks (e.g., Tailwind, SCSS)
Git, REST APIs, Webpack, and CI/CD pipelines
 Strong grasp of API design, data modelling, and error handling Experience with monitoring tools (Prometheus, Grafana)