Contract help for Windows desktop software that has to keep working.
I'm Vlad Fedoniuk — 14 years of commercial .NET, most of it WPF desktop software that's still in production. I design, build, ship and maintain Windows apps solo, and I take on a small number of contracts for companies that need the same done to theirs.
.NET Framework → modern .NET for WPF and WinForms apps, migrated incrementally while the app keeps shipping.
Steady, careful work on the WPF / WinForms line-of-business apps your team doesn't have hands for.
Unmaintained or inherited code: I stabilise it, document it, and get releases moving again.
A defined migration or upgrade, quoted as a deliverable with an end date — not open-ended hours.
My own products are the portfolio: production WPF software I design, ship and maintain solo — architecture, UI, installers, code signing, auto-updates, support.
Commercial FTP & cloud client with paying users. Shipped 2023, updated every few weeks since.
Commercial Windows backup tool on the same engine. Shipping mid August 2026.
Five more shipped Windows apps — notes, RSS, charting, uptime monitoring — all live on the main page.
Private C# development — a seven-month, 399-hour engagement for a client who'd been hiring contractors since 2006.
"He's the absolute best I've hired, in the top 10 of all my contractors, ever. His C# work is incredible … I'd re-hire him in an instant. He over-delivered on everything and he was a joy to work with." — 5.0★ client review
Senior .NET developer, full-time — a two-year, 3,195-hour embedded engagement (2018–2021).
"Vlad is a very strong developer and a team player. He worked on complex tasks and always delivered the best result." — 5.0★ client review
WPF MVVM desktop application for the shipping domain — scoped, built and delivered fixed-price in three weeks.
"It was an absolute pleasure working with Vlad. Great communication, great ideas and great execution. I would highly recommend him to anyone …" — 5.0★ client review
27 contracts · 4,000+ hours · 100% Job Success across client work
- Toptalmember of the top-3% screened network · profile ↗
- Upwork5.0 · $100k+ earned · 4,000+ hours · profile ↗
- GitHubgithub.com/vfedoniuk ↗
A small number of engagements at a time, so each gets real attention. Project-based or ongoing — both work. Remote from Poland (CET), with comfortable overlap of US and EU hours.
The fastest way to reach me:
[email protected]or LinkedIn ↗ if you prefer.