Senior Staff Ranking Engineer, Personalization

The role

You will build scalable offline and online machine learning platforms to support ranking and recommendation. You will design features, build large-scale ML models, and serve complex models in real time to help customers search and discover products.

What you will do

• Design features and build large-scale machine learning models and systems to improve ad targeting, relevance, ranking, and engagement
• Design and implement large-scale ML systems for search ranking, semantic retrieval, query understanding, and personalized product discovery
• Drive innovation in search relevance and user intent modeling using LLMs, embedding-based retrieval, and multi-modal learning
• Build and optimize ML pipelines using tools such as Apache Spark, Airflow, Kubeflow, and MLflow
• Define and track key performance metrics to evaluate model impact
• Collaborate cross-functionally with product, engineering, and data science teams
• Mentor and grow engineering talent

Required qualifications

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

Nice to have

• 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
• Experience with cloud platforms such as AWS, Google Cloud Platform including services like Vertex AI, BigQuery or SageMaker
• Experience working in startup or high-growth environments
• Proven ability to lead-cross-functional teams and deliver results in a multicultural, global organization
• Hands-on experience with modern ML frameworks such as TensorFlow, PyTorch, Scikit[1]learn, Keras, XGBoost, LightGMB, and H2o.ai
• Experience with ML lifecycle tools such as MLflow, Kubeflow, Weights & Biases, or Amazon SageMaker
• Excellent communication skills
• Demonstrated ability to work independently and manage ambiguity in fast-paced environments

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
• 6 weeks Paid Parental leave
• Pre-tax commuter benefits
• Free Electric Car Charging Station

Before you apply

• Recruitment process includes Application Review, Job Fit Interview, and Focus Interview
• Job posting may be closed prior to the stated end date if all openings are filled

About the company

Coupang is a fast-growing e-commerce company and a dominant force in South Korean commerce. It has a startup culture with the resources of a large global public company.