Sr.Staff, Back-end Engineer (Fintech Product Engineering)

Coupang is reimagining the shopping experience with the goal of wowing each customer from the instant they open the Coupang app to the moment an order is delivered to their door. Powered by an outstanding end-to-end e-commerce and logistics network and a fanatical culture of customer centricity, Coupang has broken tradeoffs around speed, selection, and price. Today, we provide exceedingly fast shipping speeds on millions of items including fresh groceries, delivered within hours nationwide, 365 days a year. We are doing this for millions of consumers in Korea. Korea is home to one of the largest and fastest growing e-commerce opportunities anywhere in the world. We have been named as one of the ‘50 Smartest Companies in the World’ by MIT Technology Review, and as one of Forbes magazine’s ‘30 Global Game Changers.’ In 2020, we placed second on CNBC’s ‘Disruptor 50’ list. Job Overview Coupang Pay is transforming the digital payments experience at massive scale—powering millions of secure transactions every day across Coupang.com, Coupang Eats, and our ecosystem of merchants and partners. We are building fast, reliable, and innovative fintech solutions that serve both consumers and businesses across Korea and beyond. We are seeking a Sr.Staff Software Engineer who is both a visionary technical leader and a hands-on builder. This role combines architectural ownership, full-stack development, and distributed systems expertise to deliver payment systems with industry-leading scale, resiliency, and speed. Key Responsibilities Hands-on Architecture Development Architect, design, and implement complex, distributed, cloud-native systems spanning frontend, backend, APIs, data pipelines, and infrastructure. Write and review production-grade code; optimize critical paths for performance, reliability, and correctness. Lead by example in code quality, observability, CI/CD, and security. Operate at Scale Speed Deliver mission-critical features to millions of users with rapid iteration while maintaining high availability and data integrity. Optimize systems for concurrency, throughput, and cost efficiency under heavy global loads. Participate in on-call rotation and drive continuous improvements in reliability and incident prevention. Full-Stack Distributed Systems Leadership Own large-scale payment microservices, event-driven pipelines, caching systems, and real-time APIs. Guide teams across web/mobile frontends, middleware, and backend services to ensure cohesive and performant experiences. Spearhead adoption of best practices in distributed computing, fault tolerance, and multi-region scaling. Innovation Emerging Technology Drive adoption of AI/ML technologies—build or integrate AI agents and intelligent automations into payment workflows. Stay ahead of fintech innovation, evaluating and deploying new technologies to improve customer experience and system resilience. Leadership Mentorship Mentor senior engineers and Sr.Staff-level peers, fostering a culture of innovation, technical rigor, and rapid delivery. Collaborate cross-functionally with product, design, and infrastructure leaders to shape both technical vision and product strategy. Qualifications Bachelor’s degree in Computer Science, Software Engineering, or related field. 12–15+ years of software engineering experience, with proven success in large-scale distributed systems. Deep expertise in full-stack development (Java, Go, Python, JavaScript/TypeScript, or equivalent). Hands-on architecture and design experience with microservices, event-driven systems, APIs, and real-time data processing. Strong fundamentals in algorithms, data structures, concurrency, and system design. Proven ability to deliver rapidly and reliably in fast-paced, high-growth environments. Preferred Qualifications Master’s or PhD in Computer Science or related technical discipline. Payment systems experience at top global fintech companies (e.g., Stripe, PayPal, Razorpay, Jus ... (truncated, view full listing at source)