Denis D.

"Hands-down, one of the best devs I've worked with on Upwork." - ScreenStory Senior C++ Engineer with 18+ years building real-time and embedded systems, multimedia pipelines, and high-performance desktop applications. Top Rated Plus on Upwork - 9,900+ hours and $400K+ earned across 28+ long-term engagements. MORE FROM CLIENTS "Excellent in every regard: communication, work, making logical inferences, asking good questions. Truly the top of the top." - Skan AI "A very reliable, knowledgeable and professional developer who is a pleasure to work with." - Clickdrive WHAT I BUILD - Rich UI/UX and high performance desktop applications on C++/Qt, C# .Net Framework WPF/UWP/WinUI XAML - Multimedia & Real-Time Screen recording engines (Desktop Duplication API, Windows Graphics Capture, GDI), low-latency video/audio pipelines on FFmpeg, WebRTC streaming with custom builds and Janus SFU, DirectX GPU compositing with custom pixel shaders, audio DSP with RNNoise. - Embedded & HMI Industrial automation, locomotive on-board systems, HMI on Qt/QML, ModBus / RS-232/485 / Can. Codex industrial labeling software for ALE sas - Real-Time Backends SCADA alarm-module backend with high-throughput low-latency event handling, gRPC, multithreaded C++17/20 architecture. - Native Library Bindings C++ cores with bindings to Electron (Node-API), Flutter (FFI), Python. Cross-platform Windows and macOS. - Engineering Infrastructure CI/CD on Jenkins and Azure DevOps, self-hosted Sentry deployment, CrashRpt, automated quality gates, structured Git workflows. HIGHLIGHTS - 7 years as lead engineer on a portfolio of consumer multimedia and document-processing applications (architecture + implementation across a team of 3) - Locomotive driver HMI deployed on operational locomotives in real-world service - Automated engine test bench: reduced testing time by 40%, increased throughput from 6 to 10 engines per shift - Currently leading C++/MFC -> Qt migration on the Ham Radio Deluxe product suite (41,500+ active users) Core stack: C++ (17/20) · Qt (QML, QWidgets) · CMake · vcpkg · FFmpeg · WebRTC · Desktop Duplication API · Media Foundation · DirectX · MFC · gRPC · Multithreading · ModBus · Windows Embedded · C# .NET · Electron Node-API · Jenkins · Azure DevOps · Sentry WHAT I'M LOOKING FOR Long-term engagements (6+ months) where deep C++ expertise and architectural ownership matter. Equally comfortable in greenfield architecture and rescuing legacy codebases. Available for fixed-price projects and hourly contracts.