Staff Backend Engineer (Streaming & AI Infrastructure)

Company Introduction 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 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. Role Overview As part of our Application Infrastructure org, this is a team building Coupang’s next-generation Real-Time Streaming & AI Platform that powers the end customer website and mobile apps . We are looking for a visionary Staff Software Engineer to lead the architectural design of a platform capable of processing over 100k+ events per second with sub-second, end-to-end latency . This system will serve as the central nervous system for Coupang, enabling real-time product and customer data and instant personalization. You will build a system that doesn't just meet industry standards but sets them, ensuring 5-6 nines availability while leveraging AI to optimize data flows and automate complex system behaviors. Responsibilities Architect for Velocity: Lead the end-to-end design of a distributed streaming engine. You will Build the Best Team and Help Them Grow by setting the gold standard for high-throughput, low-latency architectural integrity. Define Extreme Performance: Design for "5-6 nines" (99.9999% availability) at a throughput of 100k+ events/sec. You will Dive Deep into JVM tuning, memory management, and network I/O to ensure sub-second latency across global clusters. AI-Driven Streaming: Integrate AI/ML models directly into the stream processing path. Implement predictive scaling and intelligent load balancing to ensure we Wow the Customer through seamless, real-time platform responsiveness. Solve Hard Problems: Address challenges related to distributed consistency, at times, exactly-once processing guarantees, and backpressure management. You must Be Data-Driven to validate architectural decisions against massive, bursty traffic patterns. Lead with Influence: As a Staff Engineer, you will Influence without Authority , collaborating with domain teams to migrate legacy batch processes to real-time streaming architectures. Basic Qualifications Bachelor's degree in Computer Science, Electrical Engineering, Math, or a closely related field. 6+ years of experience in backend software development. Expert-level experience in Cassandra, TiDB, or DynamoDB Expert-level proficiency in Java and the Spring Framework. Demonstrated experience in building and maintaining highly available, distributed systems in cloud environments (AWS). Experience with high-volume messaging systems (e.g., Kafka, SQS). Preferred Qualifications Extensive Experience: 10+ years of professional software development experience building backend infrastructure that supports global-scale, real-time traffic. Performance Expert: Proven track record of optimizing JVM applications for ultra-low latency (<100ms p99s) and high concurrency. AI Integration: Experience or a strong architectural vision for using AI/ML to automate system-level functionality, such as real-time anomaly detection in data streams. Distributed Systems Expert: Deep understanding of the CAP theorem, consensus algorithms, and building fault-tolerant systems from the ground up. Observabi