Designed and developed REST API services for retrieving and processing complex data from PostgreSQL databases, including pension and tax records.Implemented DTO models for data tables, enabling smooth data handling and transformation between different system layers.Configured ELK logging with custom markers for unauthorized IP accesses and integrated logs based on system aspects to enhance monitoring and debugging.Developed search functionality across four tabs (IIN, BIN, names, company names) with intelligent lookup mechanisms that retrieve IIN/BIN first, enabling further data access.Built and maintained a Neo4j module for relationship queries using IIN/BIN as unique identifiers, visualizing connections in a front-end interface with dynamic filtering based on user permissions.Integrated Vis.js for rendering network data, transforming database results into DTO models for visualization.Created a notification system using aspects that alerts administrators via email of any system violations, ensuring security and compliance.