About us:
Working at Tech Holding isn't just a job, it's an opportunity to be a part of something bigger. We are a full-service consulting firm that was founded on the premise of delivering predictable outcomes and high-quality solutions to our clients. Our founders and team members have industry experience and have held senior positions in a wide variety of companies - from emerging startups to large Fortune 50 firms - and we have taken our combined experiences and developed a unique approach that is supported by the principles of deep expertise, integrity, transparency, and dependability.

The Role:
We are looking for a senior Windows systems engineer to build and maintain a production-grade Windows sync client using Microsoft's Cloud Files API (CF API). You will own the low-level plumbing that makes seamless, on-demand file synchronization feel invisible to end users, from placeholder hydration and shell overlay icons to Explorer context menus and high-throughput I/O. This is a deeply technical IC role. You will work closest to the metal of the Windows platform,



collaborating with product and backend teams to ship a sync client that rivals OneDrive and Dropbox in quality and reliability.

Key Responsabilities:
- Design and implement a Windows Cloud Files API (CF API) sync provider, including placeholder management, hydration/dehydration callbacks, and range-based partial hydration.
- Build robust Windows Shell integration: overlay icons, right-click context menus, and deep Windows Explorer integration via COM.
- Own Win32 and NTFS-level file system interactions, including extended attributes, reparse points, and oplocks.
- Implement high-performance I/O using IOCP and Windows thread pool APIs to handle concurrent file transfers reliably.
- Write and maintain COM servers and in-process shell extensions that meet Microsoft's strict reliability and compatibility requirements.
- Debug complex race conditions, kernel-mode interactions, and edge cases introduced by ant

📌 Windows Extension Developer (Guadalajara)
🏢 Tech Holding
📍 Guadalajara