Back End Engineer

The fintech business of Coupang is reimagining financial services for both our consumers and sellers, so they can do more with their money.   Coupang Pay focuses on delivering innovative payment and financial services solutions to everyone who uses the Coupang app — from customers buying products on Coupang.com, to marketplace vendors, and restaurants that offer their services via Coupang Eats. We develop solutions with our latest tech innovations to serve the growing needs of Coupang’s customers in Korea and Taiwan. This includes Coupay, an online wallet with a proprietary one-touch payment capability.    In particular, we are rapidly scaling the Wow credit card, a co-branded card that offers industry-leading rewards as part of our efforts to maximize customer values. For sellers, we are building out multiple liquidity options to help small and medium sized enterprises grow their business, using BaaS (Banking as a Service) capability.   If you want to leverage your extensive experience within the fintech space, join us. We help customers spend less time checking out so they can spend more time shopping for what they love.

Key Responsibilities

We are seeking a Sr. Staff Back-end 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.

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.