Senior .NET / C# Software Engineer (Windows Systems) Warsaw

Job Title: Senior Windows Software Engineer (C# / .NET) About the Role & Product: Adaptiq is looking for a Senior Windows Engineer to join an international product team developing a mature commercial enterprise platform. You will work on a substantial codebase, driving features from investigation through implementation to production support, while optimizing system performance and modernizing core components. Key Responsibilities: - Develop and maintain Windows-based software primarily using C#/.NET. - Investigate complex issues, debug, and optimize software performance across a mature codebase. - Work with legacy components, including C++ code when necessary. - Take end-to-end technical ownership of feature delivery and problem resolution. - Use AI-assisted development tools (Copilot, Cursor, etc.) in your daily engineering workflow. Required Skills: - 6+ years of professional software engineering experience with strong expertise in C#/.NET. - Proven track record in developing and maintaining Windows-based desktop/system software. - Strong debugging, performance profiling, and problem-solving skills in complex codebases. - Readiness to read, debug, and modify existing C++ code. - Practical experience with modern AI coding tools. - Upper-Intermediate English level (or higher) with strong communication skills. Nice to Have: - Experience developing endpoint agents, background services (Windows Services), or long-running software. - Hands-on C++ development experience. - Background in virtualized desktop environments (VDI). We Offer: - 100% Fully Remote work model + hardware/coworking support. - 20 business days of paid vacation + national holidays. - Full legal and B2B accounting support in Poland.