NATS, an Ultra-Low-Latency Messaging and Distributed System Used by Naver Interviewers

As you work in backend development, you eventually find yourself facing a certain concern. As services multiply and traffic increases, there comes a point when simple REST communication and a CRUD-only structure begin to show their limitations. I experienced the same problem in practice and went through many trials and errors trying to balance performance with structural complexity. The solution I chose in that process was NATS. Its simple, single-binary-based setup, ultra-low-latency performance measured in microseconds, and practical feature set—from Pub/Sub and Queue Groups to JetStream—made it a highly realistic choice for actual service environments. This course is not about listing NATS’s features. Based on the problems I encountered in practice, it explains through code and workflows when and why I chose NATS and how I designed the architecture. From those new to messaging systems, to backend developers preparing for employment, and senior developers considering better architectures, this course will help everyone understand distributed systems and grow to the next level.