Sr. Staff Software Engineer, Security

🏢 Summary: Senior Staff Software Engineer (ML Infra) role focused on building scalable offline and online machine learning platforms for search, ranking, and recommendation systems. The position involves designing and optimizing big data pipelines and real-time ML inference services that process billions of user interactions and petabytes of logs. The engineer will drive end-to-end ML infrastructure to support large-scale model training and high-throughput, low-latency serving. 🗂️ Requirements: Bachelor’s degree in Computer Science, Electrical Engineering, Mathematics, Statistics or related field, 8+ years of professional experience in applied machine learning, Strong experience in machine learning, deep learning, and statistical modeling, Proficiency in Python and/or Java, Experience building production-grade ML systems, Solid knowledge of data structures and algorithms, Experience with big data processing and ETL frameworks, Experience deploying scalable data pipelines processing large-scale data, Experience building high-throughput, low-latency services, Experience with cloud platforms 📃 Skills: Python, Java, Hadoop, Hive, Presto, Spark, Scala, Airflow, TensorFlow, PyTorch, AWS, GCP, ETL, ML, DeepLearning, SQL 🏢 Description: 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 our Senior Staff Software Engineer, ML infra Engineer for Search & Discovery organization, you will be in charge of designing and implementing durable & efficient software solutions that handle massive volume of structured and unstructured data needed to train complex ML models and efficiently serve them online. The Search & Discovery organization is responsible for optimizing customers' navigation experience and driving long-term growth. Every week millions of customers use search in our app or on coupang.com, more than one third of them make purchases. Over half of the Coupang sales are directly attributed to search and recommendation. Many business initiatives and growth strategies are driven or boosted by ranking and recommendation. This role is an opportunity to build scalable offline and online ML platforms to support ranking and recommendation, and business decision making. You will be handling billions of records of user interaction data, and petabytes of raw log files, and transforming them into data objects that can be easily consumed by engineers and scientists. You will also be responsible for serving complex ML models in real time to help millions of Coupang customers search and discover products. If you are passionate about big data engineering and scalable serving systems, you want to make real business impact, and you are a true problem solver, this is the right job for you. What You Will Do Proactively drive the execution of end-to-end data platform, data quality roadmap for Search & Discovery ML efforts Take ownership, consolidate and optimize the Search & Discovery core data logging, processing, and ML model training pipelines Develop and scale data infrastructure that powers batch and real-time data processing, monitoring, and debugging for ML experiments Drive design and implementation of scalable ML based ranking system and online ML inference services Build strong cross-functional partnerships with Data Scientists, Analysts, Product Managers, Indexing Platform Engineers, Ranking Engineers and Data Platform Engineers to understand both the offline and online needs and deliver on those needs Research, analyze and select technical approaches for solving difficult and challenging development and integration problems, coach and mentor other engineers in process and methodologies Basic Qualifications Bachelor's degree in computer science, electrical engineering, mathematics, statistics or closely related fields 8 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 Qualifications Computer science fundamentals: data structures, algorithms, performance complexity, and implications of computer architecture on software performance (e.g., I/O and memory tuning) Experience with Big Data tools and ETL frameworks (Hadoop, Hive, Presto, Spark, Scala, Apache Airflow, etc.) Experience with ML frameworks such as Tensorflow and Pytorch Experience with deploying highly robust and scalable data pipelines processing petabytes of data Experience in managing mission critical services with high throughput and low latency Experience with integrating applications and platforms with cloud technologies (i.e, AWS and GCP) Strong verbal and written communication skills Ability to conduct meetings and make professional presentations, and explain complex concepts and technical material to non-technical users Experience with machine learning platform for search & discovery related rankings is a strong plus Pay & Benefits Our compensation reflects the cost of living 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 $174,000K/year to $299,000K/year. 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 wouldbe offered to the hired applicant in addition to their established salary range orwage scale. Recruitment Process and Others Recruitment Process Application Review - Phone Interview - Onsite (or Virtual Onsite) 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. Privacy Notice Your personal information will be collected and managed by Coupang as stated in the Application Privacy Notice located below:https://www.coupang.jobs/privacy-policy/ 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. Job Requisition ID: R0069890

🏢 Summary: Senior Staff Machine Learning Engineer role focused on improving product search and discovery systems through advanced machine learning, deep learning, and large language models. The position involves diagnosing bottlenecks, designing and implementing state-of-the-art solutions, and running A/B tests to enhance ranking, retrieval, recommendation, and user modeling at scale. It requires deep expertise in search and recommendation systems within large-scale distributed environments. 🗂️ Requirements: 10+ years experience in Search, Information Retrieval, Recommendation Systems, ML, DL or NLP, Proficient coding skills in Java, C++ or Python, Master’s degree in Computer Science or related field, Experience handling large-scale data in distributed systems, Proven experience delivering impactful ML projects in production environments 📃 Skills: Python, Java, C++, MachineLearning, DeepLearning, NLP, InformationRetrieval, RecSys, LLM, DistributedSystems, ABTesting 🏢 Description: Sr. Staff ll, Machine Learning Engineer - Search We exist to wow our customers. We know we’re doing the right thing when we hear our customers say, “How did we 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 entrepreneurial 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. About the Role As a Senior Staff Machine Learning Engineer in Search and Discovery, you will leverage the most advanced algorithms to improve Coupang’s product search and discovery quality. You are expected to be a leading expert in one or multiple areas including information retrieval, recommendation systems, machine learning, deep learning or natural language processing. 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 Root causes the bottle neck of the current search and recommendation systems and quantifies the defects. Propose solutions which address the search and discovery defects and leverage the state-of-the-art technologies, including ML, DL and large language model. Implement the solutions and conduct AB tests. Be a thought leader and able to gain consensus in the organization when needed. Some example projects include: Personalization ranking model and its integration to Search ranking stack. Personalized retrieval Recommendation model for all Discovery interfaces. User understanding and modeling What We’re Looking For Required Qualifications 10+ years of experience in related fields including Search, Information Retrieval, RecSys, ML, DL or NLP. Proficient coding skills in Java, C++ or Python Problem solver, Pragmatic and Open-minded Master Degree in Computer Science or related fields. Experience with handling large data volumes in a distributed environment Preferred Qualifications Love to explore new territory of technology andgo deep ondomainknowledge. Ability to think outside-the-box and challenge conventional wisdom. A passion to explore, improve, automate and optimize distributed systems and tools. PhD in Computer Science or related Engineering majors Bonus points for experience at ecommerce or social network or search companies 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 $187,000/year in our lowest geographic market to $322,000/year in our highest geographic market. Pay is based on several factors including market location and may vary depending onjob-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 commuterbenefits 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. Equal Opportunities for All Coupang is an equal opportunity employer. Our unprecedented success could not be possible without the valuable inputs of our globally diverse team. 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 reasonable accommodation in the application of recruiting process due to a disability, please contact us atusrecruiting@coupang.com.

🏢 Summary: Staff Engineer role focused on leading the design, evolution, and reliability of a high-scale distributed backend platform that generates and distributes real-time customer offers. The position combines deep hands-on backend engineering with architectural leadership in event-driven systems. It emphasizes scalability, performance, observability, and operational excellence in a complex production environment. 🗂️ Requirements: Experience owning complex backend systems end-to-end in scalable production environments, Proven experience designing and operating distributed systems, Strong backend engineering expertise in Java, Solid understanding of JVM performance, Hands-on experience with Apache Kafka, Hands-on experience with Spring Boot and/or Vert.x, Hands-on experience with Redis, Hands-on experience with OpenSearch or Elasticsearch, Experience with observability tools such as Datadog, Grafana, or Kibana, Strong system design skills in event-driven and asynchronous architectures, Knowledge of concurrency and non-blocking system design, Experience with scalability, resiliency, and fault-tolerance strategies, Experience debugging production incidents in distributed environments 📃 Skills: Java, JVM, Kafka, Spring, Vert.x, Redis, OpenSearch, Elasticsearch, Datadog, Grafana, Kibana, Kubernetes 🏢 Description: ABOUT THE ROLE We are looking for a passionate and highly experienced Staff Backend Engineer to help lead the design, development, reliability, and evolution of a complex distributed backend platform. This role is ideal for someone who enjoys going deep into understanding both the technical and business context behind problems, not just implementing solutions mechanically. We value engineers who are curious, proactive, and driven by learning - people who enjoy experimenting, challenging assumptions, and troubleshooting complex systems until the root cause is fully understood. As a Staff Backend Engineer, you will provide technical leadership across architecture, engineering practices, and platform evolution while remaining hands-on when needed. You will help teams make better technical decisions, raise engineering standards, simplify complex systems, and create solutions that balance business needs with long-term platform health. We're looking for someone who is comfortable working in ambiguity, treats failure as an opportunity to learn, welcomes constructive feedback, and leads through collaboration, ownership, and execution rather than authority. ABOUT YOUR FUTURE PLATFORM TEAM We build and operate a critical backend platform that generates, validates, and distributes customer-facing offers across multiple markets in real time. The system sits at the intersection of pricing, configuration, compliance, and localization - where milliseconds matter, correctness is non-negotiable, and small mistakes can have large-scale impact. Our systems apply complex configuration and licensing rules, handle market and event-level blocking, manage multi-language localization, and transform raw pricing data into customer-ready offers consumed across the ecosystem. We process high-throughput event streams, deal with constantly changing data, and solve problems that require both strong engineering fundamentals and deep domain understanding. Success means no incorrect or missing offers in production, near real-time reflection of pricing and configuration changes, fully compliant offers across jurisdictions, and seamless multi-language experiences for customers. Our ecosystem is built around: Event streaming and backbone: Apache Kafka Backend services: Java 23+ with Spring Boot and Vert.x (we are continuously evolving toward highly reactive, asynchronous, and event-driven architecture) State and performance optimization: Redis Search and analytics: OpenSearch / Elasticsearch Observability and operations: Datadog, Grafana, Kibana Runtime and scalability: Kubernetes-based containerized infrastructure We are actively evolving our platform toward more reactive, asynchronous, and event-driven architectures, making this an exciting environment for engineers who enjoy distributed systems, performance, concurrency, and real-time data processing challenges. WHAT YOU'LL DO Technical Leadership Leading architecture and design discussions for scalable, resilient distributed systems Collaborating with Architects and senior engineers to define solution approaches and evaluate new technologies through spikes and PoCs Improving and simplifying existing system designs while maintaining high engineering standards for performance, correctness, and maintainability Maintaining a strong engineering bar across quality, scalability, and maintainability Platform Reliability & Engineering Excellence Proactively identifying scalability, reliability, and performance risks across the platform Leading debugging and root cause analysis for complex production incidents Improving observability, monitoring, alerting, and operational readiness Driving technical debt reduction and continuous platform improvement Promoting best practices across event-driven systems, resiliency patterns, performance optimization, testing, automation, and CI/CD Team Enablement & Collaboration Supporting day-to-day technical coordination within the team and contributing to incident handling and engineering discussions Mentoring engineers through design reviews, code reviews, and hands-on technical guidance Supporting cross-team collaboration and helping troubleshoot integration and platform issues Encouraging a culture of collaboration, clarity, and shared ownership Actively participating in engineering communication channels and helping unblock others Delivery & Execution Working closely with Product, Engineering Managers, and Architects to translate ideas into executable technical solutions Helping define and break down EPICs and technical initiatives in Jira Driving clarity in ambiguous or complex technical initiative Ensuring alignment between short-term delivery needs and long-term platform evolution WHAT WE'RE LOOKING FOR Required Experience: Experience owning complex backend systems end-to-end in scalable production environments Proven experience designing and operating distributed systems Strong backend engineering expertise in Java, with solid understanding of JVM performance Hands-on experience with: Apache Kafka and event-driven architectures Spring Boot and/or Vert.x Redis for low-latency and stateful use cases OpenSearch / Elasticsearch for querying and analytics Observability tools such as Datadog, Grafana, or Kibana Strong system design skills, including: Event-driven and asynchronous architectures Concurrency and non-blocking system design Scalability, resiliency, and fault-tolerance strategies Evaluating trade-offs between latency, throughput, and consistency Experience debugging production incidents in distributed environments Strong communication skills and ability to influence technical decisions across teams Proactive mindset with strong ownership and accountability Comfortable working in complex, fast-paced engineering environments Collaborative approach and willingness to support and mentor others Nice to Have: Kubernetes and cloud-native infrastructure experience Experience building internal platforms or shared engineering frameworks SRE mindset and operational excellence practices Experience with real-time or high-throughput data systems Experience leading cross-team technical initiatives WHAT SUCCESS LOOKS LIKE Teams rely on you for technical direction and practical problem-solving The platform becomes more reliable, scalable, and easier to operate over time Production incidents decrease due to proactive engineering and improved system design Cross-team dependencies are better coordinated and easier to manage Engineering quality and consistency improve across services and squads Engineers grow technically through your mentorship and guidance WHAT WE OFFER Competitive salary aligned with your experience, expertise, and impact A collaborative, inclusive, and fast-paced engineering environment where ideas are welcomed, ownership is encouraged, and continuous learning is valued Hybrid work policy 4 weeks of Workation (T&C apply) Benefits package - 800 PLN net (B2B)/gross (UOP) monthly with access to the cafeteria platform (private medical care, insurances, sports card) Training budget ICAS assistance program that can provide help and guidance during challenging moments. Our office provides complimentary snacks and drinks; on Mondays, we serve complimentary breakfast. Team and office social events throughout the year Free parking for bicycles and motorcycles Free gym in the building Equipment: MacBook Pro + smartphone (iPhone 16/17 or Samsung Galaxy S25)

🏢 Summary: Senior Software Engineer responsible for defining technical standards and architecture, leading backend and frontend development, and ensuring secure, scalable, and observable solutions. The role drives CI/CD, enterprise integrations, and production support while aligning engineering practices with product and operations goals. 🗂️ Requirements: Proven experience defining technical standards and architecture, Experience with CI/CD orchestration, Experience with observability implementation, Experience implementing on-premises, hybrid, and cloud solutions, Experience leading backend and frontend architectural decisions, Experience maintaining CI/CD pipelines, Experience coordinating enterprise integrations, Knowledge of DDD and clean architecture, Expertise in Java and Spring Boot, Expertise in Python and FastAPI, Expertise in React or Angular, Experience with L2/L3 production support, Experience with Spring Security and OAuth 📃 Skills: Java, SpringBoot, Python, FastAPI, React, Angular, CICD, Observability, ServiceNow, Jira, Boomi, DDD, OAuth, SpringSecurity 🏢 Description: To strengthen the team, we are seeking a person for the role of Senior Software Engineer, responsible for defining technical standards and architecture, guiding the development team, ensuring quality practices, security, and CI/CD, and collaborating with product and operations in delivering scalable, business-aligned solutions. Main Responsibilities Define technical standards, architecture, and development practices, ensuring quality, security, performance, and resilience in production environments. Orchestrate end-to-end delivery with CI/CD and observability while promoting responsible autonomy among teams aligned with product and operational objectives. Implement on-premises, hybrid, and cloud solutions with security best practices, observability, and integration with existing systems. Lead architectural decisions in backend and frontend (Java/Spring Boot, Python/FastAPI, React/Angular), ensuring scalability, consistent testing and code reviews. Implement and maintain end-to-end CI/CD pipelines and observability (logs, metrics, distributed tracing). Coordinate enterprise integrations (ServiceNow, Jira, CRMs) and iPaaS (e.g., Boomi), including mapping, validation, and compliance. Apply practices such as DDD, clean architecture, application security, and secrets/IAM management throughout the development lifecycle. Provide technical guidance to the team, elevate quality standards, and align practices with product and operations. Lead L2/L3 support in production: incident triage and resolution, prevention escalation (on call), SLA management, and conducting post-mortems focused on root causes and corrective actions. Operate and evolve applications in on-premises, hybrid, or cloud environments: VMs, networks, VPNs, certificates, Nginx/reverse proxy, load balancing, and enhancing the security of exposed services. Key Requirements Proven ability to define technical standards, architecture, and development practices. Experience with CI/CD orchestration and observability practices. Knowledge of implementing on-premises, hybrid, and cloud solutions with security best practices. Leadership in architectural decisions for backend and frontend technologies. Experience with maintaining CI/CD pipelines and end-to-end observability. Ability to coordinate enterprise integrations and ensure compliance. Mastery of practices such as DDD and clean architecture. Technical expertise in Java/Spring Boot, Python/FastAPI, React/Angular. Experience in providing L2/L3 technical support and leading incident resolution. Expertise in security practices, including Spring Security and OAuth. Nice to Have Experience with Docker, Kubernetes, and cloud environments (Azure/AWS/GCP). Background in data management with PostgreSQL, MongoDB, and Redis. Familiarity with AI models, particularly RAG. Knowledge in security access management and policies based on the principle of least privilege.