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.