Senior Windows .Net Developer

Our Client is a fast-growing and profitable privately-owned company based in Crawley, West Sussex. With a portfolio of cloud-based real-time call and contact analytics software is delivered through their network of IT and telecoms partners around the world and have over 7,000 active customer sites.

The company have been recognised within the industry, winning the 'Best Analytics Platform' in the UC Awards 2020. They are also proud to be a part of the Cisco Partner Ecosystem and a member of the Cisco Solution Partner Program

The Role
We are seeking an experienced and highly motivated Senior .NET Windows Client Developer to join their dynamic team and help drive the design and development of advanced desktop applications for the Windows platform.
You will play a pivotal role in building high-quality, performance and robust client-side software, with deep integration into Windows OS components such as audio and video devices. You will work in a collaborative engineering environment, applying best practices in architecture, patterns, and modern .NET development.

Key Responsibilities
· Design and develop advanced Windows desktop applications using .NET (WinForms, WinUI or other relevant frameworks).
· Implement custom UI controls from scratch, ensuring usability, responsiveness, and aesthetic polish.
· Build structured, scalable architectures following MVVM/MVC patterns, and other best practices, including plug-in design pattern approaches.
· Interface with Windows OS APIs, including audio/video subsystems, device enumeration, and media handling.
· Develop and maintain high-performance applications with a strong focus on runtime efficiency, resource management, and low-latency responsiveness.
· Work with internal teams to integrate with external systems, events, and application services via REST, sockets, or similar protocols.
· Ensure code quality via thorough testing, peer reviews, and automated CI pipelines.
· Contribute to architectural decisions, design reviews, and technical strategy.
· Maintain documentation, troubleshooting guides, and release notes as part of a quality delivery process.
Required Skills & Experience
· 7+ years of professional experience in software development using C# and the .NET Framework (.NET Core or .NET 4/5/6/7+).
· Proven track record in developing Windows desktop applications with technologies such as WinForms, WinUI, or equivalent.
· Strong capability in custom control development and UI rendering techniques.
· Proficiency with Windows API (Win32/COM), media devices (audio/video), and OS-level integration.
· Experience with architectural patterns like MVVM, MVC, and dependency injection frameworks.
· Good working knowledge of performance profiling and memory management in Windows client applications.
· Comfortable working with version control (Git), DevOps pipelines, and modern CI/CD workflows.
· Excellent problem-solving and debugging skills.
· Strategic and critical thinker capable of balancing technical, business, and operational needs.
· Excellent planning, organisational and communication skills.
· Experience in cloud-native application design and architecture.
· Self-starter with strong ability to work under their own initiative

Desirable Skills
· Exposure to SIP protocol and telecoms platform integration (e.g., VoIP, softphones, PBX systems).
· Experience developing cross-platform applications, particularly for macOS using .NET MAUI, Xamarin, or native tooling.
· Familiarity with cloud-connected desktop clients (AWS or Azure integration).
· Understanding of accessibility and internationalisation in Windows apps
· Experience with security best practices in client/server environments.
· Exposure to compliance and regulatory requirements (e.g., ISO 27001, SOC 2).

What We Offer
· Competitive salary and benefits package.
· A dynamic, supportive work environment focused on innovation and growth.
· Flexibility in working hours and remote working options.
· 25 Days Holidays (increasing by 1 day for every year in service until 30 days) + 1 Day Birthday
· EV salary sacrifice car scheme
· Private medical insurance

Spectrum IT Recruitment (South) Limited is acting as an Employment Agency in relation to this vacancy