I will fix bugs or add features to your winforms or wpf desktop app

J
juan_sls
J
juan_sls
Juan S.
fix bugs or add features to your winforms or wpf desktop app
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fix bugs or add features to your winforms or wpf desktop app
Full Screen
Full Screen
fix bugs or add features to your winforms or wpf desktop appfix bugs or add features to your winforms or wpf desktop appfix bugs or add features to your winforms or wpf desktop app

About this gig

Your business depends on a Windows desktop application, but the original developer is gone and that one bug keeps coming back.


I fix bugs and add features to existing C# desktop applications built with WinForms or WPF, on .NET Framework or modern .NET. I also work with VB.NET.


Common requests:

  • Crashes, error messages and frozen screens
  • Wrong calculations or data not saving correctly
  • New screens, fields, filters or search
  • Export to Excel or PDF
  • Slow screens caused by database access (SQL Server)

How I work:

  • I reproduce the problem first, so I fix the real cause
  • Small, focused changes, each one explained in plain English
  • You get the updated source code, tested and building
  • Your code stays private, NDA available

If the fix turns out bigger than the package, I stop and tell you before doing extra work. No surprise charges.


Not sure which package fits? Send me a message with a screenshot and I'll tell you honestly.

  • Programming language

    • C#

  • Expertise

    • Debugging
    • Performance

  • Frontend framework

    • WPF
    • WinForms

  • Backend framework

    • .NET Framework

Get to know Juan S.

Juan S.

Desktop App and SQL Server Developer for Reports and Legacy Migration

  • FromMexico
  • Member sinceNov 2026

  • Languages

    Spanish, English
Software developer in Guadalajara, Mexico. Every day I build C# / .NET desktop apps, SQL Server databases and business reports. I help small businesses keep their software alive: migrating VB6 and .NET Framework apps to modern .NET, fixing WinForms and WPF apps, speeding up slow SQL queries and building SSRS and Crystal reports. I also edit short vertical videos in Spanish for local businesses. I work in English and Spanish, on Central Time. Message me before ordering and I'll tell you honestly if I'm the right fit.

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