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I am a Back-End and Desktop Developer with 3+ years of commercial experience building scalable web APIs, financial systems, and cross-platform desktop applications. I enjoy crafting robust, maintainable code and collaborating with cross-functional teams to deliver reliable software that users love. In my recent roles I implemented integrated document exchange (PEPPOL/OIUUBL) with partners and public institutions, wrote integration and unit tests, and helped design modular architectures using MVVM and SOLID principles. I thrive in Agile environments and continually look for opportunities to improve performance and developer experience.…I am a Back-End and Desktop Developer with 3+ years of commercial experience building scalable web APIs, financial systems, and cross-platform desktop applications. I enjoy crafting robust, maintainable code and collaborating with cross-functional teams to deliver reliable software that users love. In my recent roles I implemented integrated document exchange (PEPPOL/OIUUBL) with partners and public institutions, wrote integration and unit tests, and helped design modular architectures using MVVM and SOLID principles. I thrive in Agile environments and continually look for opportunities to improve performance and developer experience.

Sergey Bonislavskyi

Back-End Developer, Front-End Developer, Full Stack Developer, +2

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I am a Back-End and Desktop Developer with 3+ years of commercial experience building scalable web APIs, financial systems, and cross-platform desktop applications. I enjoy crafting robust, maintainable code and collaborating with cross-functional teams to deliver reliable software that users love. In my recent roles I implemented integrated document exchange (PEPPOL/OIUUBL) with partners and public institutions, wrote integration and unit tests, and helped design modular architectures using MVVM and SOLID principles. I thrive in Agile environments and continually look for opportunities to improve performance and developer experience.…I am a Back-End and Desktop Developer with 3+ years of commercial experience building scalable web APIs, financial systems, and cross-platform desktop applications. I enjoy crafting robust, maintainable code and collaborating with cross-functional teams to deliver reliable software that users love. In my recent roles I implemented integrated document exchange (PEPPOL/OIUUBL) with partners and public institutions, wrote integration and unit tests, and helped design modular architectures using MVVM and SOLID principles. I thrive in Agile environments and continually look for opportunities to improve performance and developer experience.

Available to hire

I am a Back-End and Desktop Developer with 3+ years of commercial experience building scalable web APIs, financial systems, and cross-platform desktop applications. I enjoy crafting robust, maintainable code and collaborating with cross-functional teams to deliver reliable software that users love.

In my recent roles I implemented integrated document exchange (PEPPOL/OIUUBL) with partners and public institutions, wrote integration and unit tests, and helped design modular architectures using MVVM and SOLID principles. I thrive in Agile environments and continually look for opportunities to improve performance and developer experience.

Skills

ASP.NET

.NET

XML

Experience Level

Expert

ASP.NET

Expert

.NET

Expert

XML

Intermediate

Language

English

Fluent

Russian

Fluent

Ukrainian

Fluent

Danish

Beginner

Work Experience

Back-End Developer at Consult A/S – Denmark (Remote)

January 1, 2022 - August 1, 2024

Implemented scalable web APIs and financial systems; integrated PEPPOL/OIUUBL e-document exchange with partners and public institutions; implemented import/export endpoints for standardized document templates (Word/Excel); wrote integration and unit tests covering critical financial workflows; collaborated in an Agile environment to deliver incremental features and improve data exchange efficiency.

Back-End Developer (Diploma Project) at Diploma Project – Borys Grinchenko Kyiv University

June 1, 2024 - May 1, 2025

Designed and implemented a cross-platform desktop application (MVVM) using Avalon UI and XAML; migrated Electron-based JS UI to C# with Avalonia UI, delivering a modular, scalable architecture and configurable layouts.