Enterprise support for legacy VSTO add-ins.

While Microsoft is heavily investing in Office JS and recommends it for all new development, VSTO remains supported on Windows desktop versions of Office. However, VSTO will never be supported on Mac or Web.

Yes. We frequently take over "orphaned" codebases. Our first step is always a thorough code audit to understand the architecture, document the logic, and identify critical vulnerabilities.

It depends on your timeline and budget. If you need a quick feature to unblock the business, we can add it to VSTO. But if you are planning significant updates, we strongly recommend redirecting that investment toward an Office JS migration.

Yes, we are highly experienced in troubleshooting and resolving complex MSI, ClickOnce, and registry deployment issues across enterprise Windows environments.

We resolve deployment issues by migrating away from fragile MSI installers towards robust ClickOnce deployments, ensuring strong-naming of assemblies, and strictly managing GAC (Global Assembly Cache) dependencies.

Yes. We specialize in inheriting legacy, undocumented VSTO codebases. We refactor monolithic logic into modular MVVM architectures, update outdated third-party NuGet packages, and fix memory leaks causing Office crashes.

We optimize COM Interop by minimizing the number of calls across the boundary. Instead of reading cells one by one, we read massive Excel ranges into C# 2D arrays, process the data asynchronously (Task.Run), and write back in bulk.

Absolutely. We utilize modern .NET HttpClient libraries within VSTO to establish secure TLS 1.2+ connections, handle complex JSON serialization, and manage OAuth tokens to integrate desktop Office with cloud APIs.

We utilize the `ComAddIn.Object` property to expose specific C# classes and methods directly to the VBA environment, allowing legacy macros to call powerful, compiled .NET backend logic securely.

ClickOnce deployments require valid Code Signing Certificates (EV is preferred) to bypass Windows SmartScreen warnings and satisfy Office Trust Center requirements, ensuring users only install verified, tamper-proof binaries.