Windows Cloud Sync Engineer

This is a remote position.

Job Role:Windows Cloud Sync Engineer

Experience: 6+ Years

Location: Remote

About the Role

We are building a high-performance Windows desktop application that seamlessly synchronizes customer files from the Cloud directly into Windows File Explorer. This role focuses on developing a robust cloud sync engine using native C++, creating a C++/CLI interop layer to integrate with a .NET 8.0 application, and implementing deep Windows File Explorer integration using the Windows Cloud Filter API.

The ideal candidate has strong Windows systems programming expertise, modern C++ proficiency, and experience building production-grade desktop software optimized for performance, reliability, and maintainability.

Key Responsibilities

• Design and implement a cloud file synchronization engine for Windows
  
• Build and maintain a C++/CLI mixed-mode interop layer between native C++ and .NET 8.0
  
• Integrate deeply with Windows File Explorer using the Cloud Filter API (cfapi.h)
  
• Implement file system callbacks, sync root registration, and on-demand file hydration
  
• Develop multi-threaded, asynchronous components optimized for performance and stability
  
• Work across managed and unmanaged boundaries to debug and resolve complex issues
  
• Collaborate with .NET developers to deliver a seamless desktop experience
  
• Ensure production-quality code with a focus on reliability, security, and maintainability
  

Must-Have Qualifications

Cloud Sync Engine Development

• Hands-on experience with Windows Cloud Filter API (cfapi.h) or similar OS-level file sync technologies
  
• Strong understanding of:
  
• Sync root registration
  
• Placeholder file states
  
• On-demand hydration patterns
  
• Experience implementing native file system callback handlers
  

Modern C++ (C++20)

• 5+ years of professional native C++ development on Windows
  
• Strong expertise in modern C++ features:
  
• std::variant, std::optional, std::string_view
  
• Lambdas, std::function, functional programming patterns
  
• Template metaprogramming and variadic templates
  
• Deep understanding of memory management, RAII, and pointer safety
  

C++/CLI Interoperability

• Experience developing C++/CLI mixed-mode assemblies targeting .NET Core / .NET 8.0
  
• Ability to design ref class wrappers exposing native C++ functionality to managed code
  
• Strong understanding of managed vs unmanaged compilation boundaries
  
• Experience with string marshaling between std::wstring and System::String^
  

Windows Systems Programming

• Strong knowledge of Win32 API, Windows Shell APIs, and File System APIs
  
• Proven experience in multi-threaded programming:
  
• Thread pools and work scheduling
  
• Synchronization primitives (std::mutex, std::shared_mutex, reader-writer locks)
  
• Async and callback-based architectures
  
• Familiarity with Windows SDK 10.0 and Windows 10+ targeting
  

COM Programming

• Experience implementing COM components:
  
• IUnknown, reference counting, class factories
  
• Knowledge of DLL exports:
  
• DllGetClassObject, DllRegisterServer, DllUnregisterServer
  
• Understanding of registry-based COM registration
  

Build Systems & Tooling

• Proficiency with Visual Studio 2022 for mixed C++/C# solutions
  
• Experience with MSBuild and .vcxproj configuration
  
• Strong debugging skills across managed and unmanaged code
  

Nice-to-Have Qualifications

Windows Shell Extensions

• Experience building shell extensions such as:
  
• Context menu handlers (IContextMenu, IShellExtInit)
  
• Icon overlay handlers
  
• Property handlers
  
• Knowledge of Windows Explorer integration patterns
  

.NET Desktop Development

• Experience with .NET 8.0 WPF desktop applications
  
• Familiarity with MVVM architecture and data binding
  
• Ability to contribute to C# codebases when required
  

Database & Serialization

• Experience using SQLite via the C API
  
• Familiarity with nlohmann/json or similar C++ JSON libraries
  

Installer & Deployment

• Experience with NSIS installer scripting
  
• Knowledge of WiX Toolset v4 for MSI creation
  
• Understanding of enterprise-grade Windows installer best practices
  

CI/CD & Testing

• Experience with GitHub Actions for Windows CI pipelines
  
• Familiarity with testing strategies in mixed C++/.NET environments
  
• Experience with unit, integration, and end-to-end testing
  

Security & Authentication

• Experience with Windows Credential Manager
  
• Understanding of OAuth 2.0 authentication flows in desktop applications
  
• Knowledge of Windows security models and file system permissions
  

Logging & Observability

• Experience with structured logging (ECS / Elastic Common Schema)
  
• Familiarity with centralized logging solutions such as Elasticsearch
  

Bonus Points

• Prior experience building cloud sync clients (e.g., OneDrive, Dropbox, Google Drive-style architectures)
  
• Experience with chunked or resumable file upload and download mechanisms