Comparative performance analysis of Spring Boot and Ktor for a ticket reservation REST API on the JVM

This paper presents an experimental comparison of Spring Boot and Ktor as backend frameworks for REST API development on the JVM platform. The study was motivated by the need for a controlled evaluation of these frameworks, since available comparisons are often based on non-uniform assumptions and do not clearly separate framework-related effects from other implementation factors. To ensure comparability and reduce the influence of external variables, two reference applications implementing the same ticket reservation business scenario and sharing the same PostgreSQL database were developed. The evaluation was conducted with load tests covering write, read and mixed workloads. The analysis included response times, system stability, the number of successful and unsuccessful responses, as well as CPU and RAM usage. The results show that both frameworks maintained full technical correctness, while Ktor achieved lower response times and lower average CPU usage.