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

As a Staff Machine Learning Engineer for the Coupang Media Group (CMG) - Ads Quality & Ranking, you will be responsible for designing and deploying state-of-the-art machine learning models, ranking algorithms, and optimization systems powering our advertising platform.

The Coupang Media Group provides vendors and advertisers with high-impact marketing products and services directly within our e-commerce marketplace. Operating at internet scale—handling over 1 billion daily ad impressions—our platform covers complex engineering challenges across real-time behavioral targeting, automated auctioning and bidding, click-through rate (CTR) / conversion rate (CVR) prediction, and search-based advertising. In this role, you will lead the transition of our ad quality stack toward enterprise-grade ML infrastructure and extend our footprint across full-stack ad tech solutions.

What You Will Do

ML System Design & Ads Ranking

Model Development: Architect, build, and deploy large-scale machine learning and deep learning models to optimize ad targeting, relevance, ranking, and user engagement.
Algorithmic Innovation: Develop advanced techniques for automated mechanisms, including auto-bidding algorithms, query expansion, and advertiser ROI optimization models.
Marketplace Intelligence: Design systems that provide actionable suggestions and insights to advertisers, enabling them to identify growth opportunities within the Coupang marketplace.

Architecture & System Scalability

Infrastructure Strategy: Architect and evolve our end-to-end machine learning platform to serve high-throughput, low-latency ad requests at internet scale.
Technical Quality & Rigor: Maintain high standards for code quality, system reliability, and automated testing across complex distributed machine learning pipelines.

Leadership & Collaboration

Cross-Team Leadership: Lead large-scale technical projects spanning multiple engineering teams, aligning technical roadmaps with business objectives.
Mentorship: Provide technical guidance, code reviews, and architectural mentorship to mid-level and senior engineers.
Cross-Functional Partnering: Collaborate closely with Product Management, Data Science, and Business Leadership to design and deliver next-generation advertising features.

Basic Qualifications

Bachelor's degree in computer science, electrical engineering, mathematics, statistics or closely related fields
4 years of professional experience in applied machine learning
Experience in machine learning, deep learning, and statistical modeling
Proficiency in Python and/or Java, with experience in building production grade ML systems

Preferred Qualification

Master’s or PhD in relevant technical fields
Experience with search systems, information retrieval or recommendation engines
Experience with LLMs, embeddings, and vector search technologies