Senior Software Engineer
📧 [email protected]
📍 Trenčín, Slovakia
🔗 LinkedIn: linkedin.com/in/denys-kirin
🔗 GitHub: github.com/KirinDenis

Senior Software Engineer with 25+ years of experience building scalable enterprise, cloud, and embedded systems.
Specialized in .NET, Azure, and high-performance system architecture.
Strong background in designing reliable software, modernizing legacy systems, and mentoring engineering teams to deliver maintainable, production-grade solutions.

International Solomon University, Kyiv, Ukraine
Master's Degree — Computer Science

Apr 2020 – Current

Develop and maintain scalable .NET applications and microservices using C# and ASP.NET Core. Work closely with cross-functional teams to define architecture, optimize performance, and promote engineering best practices.

• Built RESTful APIs and microservices using ASP.NET Core, SignalR, and WebHooks
• Implemented SAML-based SSO and high-performance data caching with MSSQL and Redis
• Automated deployments using Azure, Docker, and CI/CD pipelines

Apr 2016 – Mar 2020

Directed technical strategy for a startup developing a unified API integration platform. Responsible for architecture, cloud infrastructure, security, and engineering leadership.

• Architected cross-platform API integration system with OAuth 2.0 authentication
• Managed Azure infrastructure and automated CI/CD pipelines
• Mentored developers and aligned engineering roadmap with business goals

Jan 2009 – Feb 2016

Designed and delivered a wide range of Windows desktop utilities and SDKs in C# and Delphi. Modernized legacy apps with migration to .NET Framework.

• Built SDKs integrating with Microsoft Outlook and Mozilla Thunderbird
• Refactored and optimized legacy codebases for performance and stability
• Mentored junior developers and improved internal coding standards

Oct 2005 – Dec 2008

Developed custom desktop applications for clients across the US, Germany, China, Canada, and Australia.

• Implemented database-driven apps and system utilities using Delphi and COM
• Developed browser extensions (ActiveX, IE SDK) and Windows automation tools
• Collaborated with distributed international teams

May 2003 – Sep 2005

Analyzed malware behavior, system vulnerabilities, and developed system-level recovery utilities.

• Extensive experience with Windows internals, debugging, and low-level API usage

Aug 1999 – Apr 2003

Developed accessibility software for visually impaired users, including speech-to-text solutions and adaptive workstations.

• Designed custom Windows applications for blind and low-vision professionals
• Delivered user training and collaborated with educators to improve usability

Active contributor to open-source projects in desktop development, embedded systems, and IoT.
Develop IoT solutions using ESP32/ESP8266, MQTT, REST APIs, and build cross-platform libraries for OpenGL ES, Xamarin/Android, Rust, and more.

• OWLOS (IoT Weather Platform):
  https://github.com/KirinDenis/owlos
• Rust Sokoban + WASM Game:
  https://github.com/KirinDenis/Base-Z-47-Rust-Game
• Windows Registry Defragmentation Tool:
  https://github.com/KirinDenis/WindowsRegistryDefrag

C#, .NET (Core & Framework), REST API, OAuth2, SAML, Redis, MSSQL, Microservices

JavaScript, TypeScript, HTML/CSS

Delphi VCL, C# WinForms, WPF, Windows API, COM/ActiveX

C/C++, ESP32, ESP8266, Arduino, STM32, PlatformIO, ESP-IDF, MQTT

Azure, Docker, GitHub, Azure DevOps, CI/CD pipelines

Rust, Reverse Engineering, Assembly, Real-time Programming, Accessibility Software

Languages:

• Ukrainian — Native
• English — B2 (actively improving, confident in professional communication)

Status: Self-employed (živnostník), EU work authorization
Driving License: Category B
Availability: Remote