Built a REST API and React frontend for helping Ukrainians abroad determine tax obligations across multiple EU countries. Implemented Clean Architecture with a four-layer split, JWT authentication with refresh-token rotation, Google OAuth integration, live exchange-rate integration, Prometheus metrics, health probes, security middleware, and xUnit tests. Containerized the stack with Docker Compose and built a bilingual UI with dark and light themes.

Developed a desktop fitness and nutrition tracking application with meal logging, calorie monitoring, and health goal management. Implemented secure authentication, integrated Firebase Firestore as a cloud backend, and applied MVVM architecture with structured logging using NLog.

Built a WPF desktop tool for generating realistic SQL test data across multiple SQL dialects. Implemented asynchronous data generation to keep the UI responsive and structured the application with MVVM for maintainability.