Backend: Python (Django, FastAPI), Java (Spring), Go, C# (.NET), PHP (7.4/8.x, Symfony, Laravel, Bitrix), Node.js, C++ (17/20, Boost.Asio), C (System programming).
Frontend: JavaScript, TypeScript, React, Vue, Angular, HTML5/CSS3.
Mobile & Desktop: iOS, Android, Flutter, Qt (C++), OpenGL, DirectX, FFMpeg.
Architecture & Patterns: Microservices, DRY, KISS, SOLID, OOP, REST API, SDK development, Highload.