Principal Engineer, ML

About the Role

What You Will Do

• Define and drive the long-term technical vision, architecture, and strategy for Coupang's Ads Serving & ML Platform.
• Lead the design and evolution of large-scale ad serving systems, including retrieval, ranking, auction, targeting, pacing, and measurement.
• Drive platform modernization and adoption of emerging technologies, including large language models, generative AI, real-time inference, and next-generation ML infrastructure.
• Identify and lead strategic technical investments that improve advertiser outcomes, customer experience, system scalability, and operational efficiency.
• Partner with engineering, machine learning, product, and business leaders to align technical direction with company priorities and business objectives.
• Influence architecture and engineering excellence across multiple organizations through technical leadership, design reviews, and mentorship.
• Establish best practices for platform reliability, performance, scalability, observability, and operational excellence.
• Drive measurable business impact through innovations that improve engagement, conversion, relevance, advertiser ROI, revenue growth, system efficiency and cost.
• Serve as a recognized technical leader and domain expert in large-scale advertising systems and machine learning platforms.

Required Qualifications

• 12+ years of experience building large-scale software platforms, machine learning systems, or distributed infrastructure.
• Proven track record of architecting and operating mission-critical, high-throughput online systems at internet scale.
• Deep expertise in one or more user-facing machine learning domains, including advertising, search, recommendations, or personalization.
• Strong understanding of modern machine learning systems, including model training, feature engineering, experimentation, online inference, evaluation, and production operations.
• Experience building and scaling AI/ML serving infrastructure, including optimization of GPU- and CPU-based systems for latency, throughput, and cost efficiency.
• Strong understanding of large language models (LLMs), foundation models, retrieval-augmented generation (RAG), and production AI serving architectures.
• Deep knowledge of retrieval and ranking systems, including: Relevance and personalization Candidate generation and ranking Precision, recall, latency, and cost trade-offs Online experimentation and model evaluation
• Relevance and personalization
• Candidate generation and ranking
• Precision, recall, latency, and cost trade-offs
• Online experimentation and model evaluation
• Demonstrated ability to drive significant business impact through technical innovation and platform evolution.
• Exceptional ability to influence technical direction across multiple teams and organizations without direct authority.
• Strong software engineering skills in Java, C++, or Python.
• Experience developing distributed systems that process and serve large-scale datasets with high availability and low latency.
• MS or above in Computer Science, Engineering, or a related technical discipline.

Preferred Qualifications

• Experience building large-scale advertising platforms, ad ranking systems, auction systems, or sponsored search products.
• Experience in e-commerce, marketplaces, or consumer internet companies operating at significant scale.
• Expertise in real-time machine learning, recommendation systems, search infrastructure, or large-scale personalization platforms.
• Proven contributions to architectural transformations or platform modernization initiatives across large organizations.
• Strong passion for exploring emerging technologies and translating innovation into business value.
• Experience working in high-growth, fast-scaling technology companies.
• PhD in Computer Science, Machine Learning, Artificial Intelligence, or related fields.

Pay & Benefits

• Our compensation reflects the cost of labor across several US geographic markets. At Coupang, your base pay is one part of your total compensation.
• The base pay for this position ranges from $207,900/year in our lowest geographic market to $386,100/year in our highest geographic market. Pay is based on several factors including market location and may vary depending on job-related knowledge, skills, and experience.
• General Description of All Benefits
• Medical/Dental/Vision/Life, AD&D insurance
• Flexible Spending Accounts (FSA) & Health Savings Account (HSA)
• Long-term/Short-term Disability
• Employee Assistance Program (EAP) program
• 401K Plan with Company Match
• 18-21 days of the Paid Time Off (PTO) a year based on the tenure
• 12 Public Holidays
• Paid Parental leave
• Pre-tax commuter benefits
• MTV - [Free] Electric Car Charging Station

General Description of Other Compensation

• “Other Compensation” includes, but is not limited to, bonuses, equity, or other forms of compensation that would be offered to the hired applicant in addition to their established salary range or wage scale.
• Coupang is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to actual or perceived race (including traits historically associated with race, including but not limited to hair texture and protective hair styles), color, religion, religious creed (including religious dress and grooming practices), sex or gender (including pregnancy, childbirth, breastfeeding, and medical conditions related to pregnancy, childbirth or breastfeeding), gender identity, gender expression, sexual orientation, ,ancestry, national origin (including language use restrictions), age (40 and over), physical or mental disability, medical condition, genetic information, HIV/AIDS or Hepatitis C status, family status (including but not limited to marital or domestic partnership status), military or veteran status, use of a trained dog guide or service animal, political activities or affiliations, ancestry, citizenship, family and medical leave status, status as a victim of any violent crime, or any other characteristic or class protected by the laws or regulations in the locations where we operate. Coupang is also committed to providing a safe work environment for its employees and its consumers If you need assistance and/or a reasonable accommodation in the application of recruiting process due to a disability, please contact us at usrecruiting@coupang.com .