● Development of REST API in Java (Spring Boot) for managing clients, applications and statuses in CRM, with correct error handling and data validation. ● Designing a database schema and database migration using Flyaway, ensuring version control and secure schema updates. ● The implementation of the collection and aggregation of information about customers and applications, which made it possible to build dashboards and reports in real time. ● Wrote unit and integration tests using JUnit and Mockito, covering key API scenarios. ● Set up logging, which made it easier to diagnose errors during the testing phase. ● Worked in the team through Git and Jira, participated in code reviews and daily meetings, receiving feedback from senior developers.