Building modern backend and web applications.

Extensible microservices architecture with automatic scaling, monitoring, and CI/CD, handling high load and ensuring low latency. Written in Go (Angular frontend), deployed on Kubernetes using Helmfile (push-based deployment), with monitoring based on Prometheus, Grafana, and Loki. The system supports core functionalities such as authorization, email communication, and payments. It uses REST, gRPC, and GraphQL and was designed for easy extensibility with new features and integrations while ensuring high availability and fault tolerance.

Lighting control system based on the Matter protocol with voice integration and automated scenarios. The project included integration with voice assistants as well as automatic operation based on schedules and presence detection.

Recipe management application with a feature that suggests recipes based on available ingredients. Backend written in Java using Spring Boot, with a Flutter mobile frontend. The application allows users to add their own recipes, rate them, and share them with others. The system uses WebFlux for asynchronous operations and high performance. Thanks to data streaming and a reactive approach, it can handle a large number of users and ensure smooth performance even with extensive recipe and ingredient databases.

Mobile application for managing debts and loans between friends with reminders and summaries. Users can add debts, define repayment dates, and send reminders to debtors. Firebase-based backend ensures scalability and reliability, while the Flutter frontend provides an intuitive user interface. The application uses Firebase Cloud Messaging to deliver push notifications, keeping users up to date with their financial obligations.

Co-development of a payment token lifecycle management system for digital wallets (including Apple Pay and Google Pay) and subscription services. The system consists of over 60 microservices operating in a regulated PCI environment, focused on high security standards and payment process automation.

Co-development of a service integrating payment cards with loyalty systems, enabling automatic assignment of e-receipts to users without requiring membership cards. The system integrates with payment terminals and processes transaction data in real time, ensuring high data quality and accurate receipt assignment, enabling effective loyalty program management.