Senior Staff Backend Engineer

About the role

We are looking for a Senior Staff Engineer to lead the design and implementation of Tier‑1 fulfillment systems that process every Coupang order in real time across Korea and Taiwan. The role combines deep hands‑on coding with broad architectural ownership, influencing millions of daily orders.

Key responsibilities

• Design and build scalable, reliable services for order planning, fulfillment optimization, inventory allocation, and network cost management.
• Own architecture of distributed systems using gRPC service meshes, Kafka pipelines, CPLEX solvers, multi‑layer caching, and multi‑region deployments.
• Write production code in Kotlin and Java, set standards for correctness, performance, and operational safety.
• Lead design and code reviews, identify correctness, scalability, and reliability issues in latency‑sensitive flows.
• Drive reliability through circuit breakers, graceful degradation, observability, and incident prevention.
• Partner with product, data science, and operations to translate optimization goals into technical execution.

Required profile

• Proven experience designing and operating high‑scale distributed systems with strict latency and reliability requirements.
• Strong hands‑on coding ability in Kotlin or Java for backend systems at scale.
• Deep understanding of API design, concurrency, data modeling, caching strategies, and service‑to‑service communication (gRPC, REST).
• Experience with event‑driven architectures using Kafka and multi‑region deployments.
• Track record of technical leadership, setting architecture direction, and mentoring senior engineers.

Required skills

• Kotlin
• Java
• Spring Boot
• gRPC
• REST
• Kafka
• CPLEX
• Python
• Redis
• Cassandra
• Elasticsearch
• Drools
• Temporal