Developed and optimized core components of a high-load payment platform, handling transaction logic and microservices architecture.

• Migrated to a new SMS provider, reducing costs by ~60%
• Implemented background services for automated transaction lifecycle management (polling, cancellation of outdated records)
• Resolved critical concurrency issues in webhook processing
• Developed automated tests
• Integrated third-party APIs and webhooks, including cryptocurrency providers

Developed and maintained ASP.NET Core web applications for a few clients, focusing on migrating legacy logic to modern APIs and optimizing database performance. Mostly fixed bugs and added new features when they needed themю.

• Optimized slow PostgreSQL queries by implementing efficient indexing and Redis caching to make the sites stop lagging
• Developed React-based front-end components
• Integrated a payment system (Stripe)
• Wrote a web scrapper for tracking goods in Ukrainian e-shop

Worked as part of a development team in an outsource company, focusing on upgrading and modernizing microservices. Worked on backend features for web applications in the .NET ecosystem. Handled bug fixes and small feature requests within a remote team.

• Upgraded and maintained multiple microservices, worked with RESTful APIs
• Implemented asynchronous messaging and event-driven communication with RabbitMQ
• Secured service-to-service communication with JWT
• Worked with AWS services (EC2, S3) for application deployment and cloud storage management