This article compares the efficiency of Java and Scala languages in data processing. Two web applications were created in these languages using the popular GraphQL interface and the H2 database. The research was conducted using test scenarios that included several data processing algorithms, varying numbers of users making requests to the application and different database sizes. Performance evaluation criteria such as data processing time, memory usage, and processor load were applied. The JMeter tool was used for the tests. The results show that the application written in Scala demonstrates higher efficiency.