Lowering the Testing Barrier at KakaoPay with a Company-Wide Shared Mock Server

KakaoPay developed a company-wide shared mock server to resolve inter-service dependency issues arising in its microservices architecture (MSA) environment. Previously, testing was often interrupted due to maintenance of specific services or integration issues with external services, and the constraints of local environments made it difficult to verify the entire flow.

For efficient development, the system was built on top of the MockServer open source, with the following core features added.

• User-friendly UI: Provides API add, edit, delete, and memo functions to increase usability
• Monitoring: Uses Prometheus and Grafana to check API call logs and server status in real time
• Backup and recovery: Automatic backup upon data changes, with a structure enabling immediate recovery when needed

For operational stability, the mock server is operated separately for two purposes. The shared mock server, which supports general development, leaves detailed user logs for easy problem tracking, while the mock server for performance testing minimizes log recording to prevent performance degradation, optimizing it for simulating large-scale traffic.

Currently, this system operates 72 mock servers across 29 organizations, contributing to improved development and testing efficiency.