Denis developed the foundational chat Q&A system for the rag2daw2025 repository, establishing a robust data model and service layer to support conversational AI workflows. He implemented advanced data filtering, dynamic queries, and real-time streaming using Java, Spring Boot, and SQL, enabling efficient retrieval and incremental delivery of chat data. On the frontend in rag2daw2025frontend, Denis reorganized the codebase for maintainability and built the core chat management UI with Angular and TypeScript, integrating Server-Sent Events for live updates. His work delivered a scalable, extensible platform that improved user experience and accelerated the development of real-time chat features.