I was hired to work on the development of a Performance Management System for the Tax Administration of the Republic of Croatia, where I served as the Lead Oracle Developer and was responsible for the full technical implementation of the application. The solution was built using Oracle Database 19c, Oracle Application Express (APEX) 22.2, and Oracle REST Data Services (ORDS).
A normalized relational schema was designed, with business logic implemented in PL/SQL, including dynamic goal cascading, performance evaluation workflows, and role-based access control (RBAC) aligned with the organizational hierarchy.
Audit-compliant data tracking was implemented using temporal tables and fine-grained auditing (FGA). Real-time reporting was developed through Oracle APEX Interactive Reports and integrated with Oracle BI Publisher for PDF and Excel exports. Query performance was optimized using indexing strategies, materialized views, and SQL tuning. RESTful APIs were developed for secure frontend integration, and asynchronous processing was implemented using Oracle Advanced Queuing (AQ).
The system can support over 100,000 users with high availability and ensured data consistency.