Windows Development · 25+ Years Experience

Build Windows apps that work hard for your business

WPF, WinForms, WinUI 3, UWP, .NET MAUI and Win32 — from greenfield builds to legacy modernisation, delivered by an experienced UK Microsoft Partner team.

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Technologies WPF WinForms WinUI 3 .NET MAUI Win32
Built with Microsoft Partner .NET 10 25+ Years Legacy & Modern
MainWindow.xaml.cs Code Preview 
// WPF + .NET 10 — MVVM with CommunityToolkit
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;

namespace Contoso.Desktop;

[ObservableObject]
public partial class DashboardViewModel
{
    [ObservableProperty]
    private int _activeUsers = 2_847;

    [ObservableProperty]
    private decimal _revenue = 148_500m;

    [RelayCommand]
    private async Task RefreshAsync()
    {
        var data = await _service
            .GetDashboardAsync();
        ActiveUsers = data.Users;
        Revenue     = data.Revenue;
    }
}

// XAML binding — zero code-behind
<TextBlock
    Text="{Binding ActiveUsers}"
    Style="{StaticResource KpiValue}" />
<Button
    Command="{Binding RefreshCommand}"
    Content="Refresh" />
Contoso Dashboard — .NET 10
Dashboard
Users
Reports
Settings
Active Users 2,847 +12%
Revenue £148k +8%
Orders 1,204 -2%
Monthly Revenue
82k
Feb
96k
Mar
111k
Apr
104k
May
129k
Jun
148k
Jul
  • Enterprise38%
  • SMB28%
  • Retail20%
  • Other14%
Live — bound via ObservableObject

We are Your Partner in Windows Development. Modernisation, Greenfield, Legacy Support.

At Assemblysoft, we're equipped to help you navigate the complexities of choosing the right technology for your Windows application development project.

Assemblysoft are Microsoft Certified Developers

Assemblysoft is fantastic to work with! They're always there when you need them, communicate really well, and make everything super easy. From the beginning to the end, they've been an awesome partner. The team's passion for what they do creates a positive vibe that makes working with them a breeze. I highly recommend Assemblysoft for their great service and commitment to making customers happy. Definitely a five-star experience!

James Smith ( Project Lead at MADC LIMITED )

Partner with us as your safe pair of Windows application development hands Microsoft Azure Developers
Yes, we are experienced with, experts at, well versed in, adept at, battle hardened with Console applications, Windows Services, .NET MAUI, Blazor Hybrid, UWP XAML (Windows.UI.Xaml), Win32 (MFC or ATL), Windows Forms, WinUI 3, WPF

Why Windows applications are still essential tools for your business in 2026?

Microsoft Azure Developers

Enhanced Productivity

Windows applications streamline business processes, enabling enhanced productivity through user-friendly interfaces and powerful automation capabilities.
DotNet Development Services

Robust Security

With advanced security features, Windows applications safeguard sensitive business data against cyber threats, ensuring peace of mind and compliance with regulations.

Blazor Developers in the United Kingdom

Seamless Integration

Windows applications can seamlessly integrate with existing software ecosystems, facilitating efficient data exchange and enhancing overall operational efficiency.
Azure DevOps Developers in the UK.

Customization and Scalability

Tailored to meet specific business needs, Windows applications offer unparalleled customization and scalability, supporting growth and evolving requirements.

Benefit from our many years of Windows application development Expertise

We are are Microsoft Partners providing you with key insights

Despite the rapid shift of businesses of all scales towards enterprise cloud-based digital solutions, there is a persistent demand for custom Windows applications.

Tell Us What You Need.

Windows Apps Customised for Your Business

Our team is committed to delivering high-quality, future-proof applications that meet your specific needs, leveraging the right technology to provide the best user experience and performance.

Rich User Experience

Leveraging the power of native Windows features, these applications deliver a rich and intuitive user experience, enhancing user satisfaction and engagement.

Long-term Support

Windows applications benefit from Microsoft's long-term support, including regular updates and patches, contributing to a secure and stable software environment.

Broad Compatibility

Designed to operate on the Windows platform, these applications enjoy broad compatibility across a wide range of hardware, ensuring accessibility and performance for all users.

Cost-Effective Deployment

Windows applications can be more cost-effective to deploy and maintain, especially for businesses already entrenched in the Windows ecosystem, reducing the need for additional infrastructure investments.

Advanced Performance Capabilities

Taking full advantage of the underlying Windows OS, these applications offer advanced performance capabilities, ensuring efficient processing and responsiveness even in demanding scenarios.

Offline Access

Windows applications provide reliable offline access, ensuring that critical business functions remain available without an internet connection, boosting resilience and continuity.

Secure

End-to-end encryption and security best practices, ensuring your data remains safe at all times and adheres to compliance standards for your business domain.

Advanced Performance Capabilities

We develop applications that take full advantage of the underlying Windows OS, these applications offer advanced performance capabilities, ensuring efficient processing and responsiveness even in demanding scenarios.

Framework Guide

Choosing the right Windows UI framework

Every project is different. Here is an honest comparison of each framework we deliver — with background, pros, cons, and our real-world take on when to use each one.

Windows Forms
Actively maintained

The original managed Windows UI platform. Forms-based rapid application development with a large library of drag-and-drop controls and access to both .NET and .NET Framework. No XAML — ideal when you want to build fast without a steep learning curve.

Pros
  • Supports C# and Visual Basic
  • Drag-and-drop designer in VS
  • Hot Reload support
  • Huge ecosystem of controls
  • Fast to prototype and ship
Cons
  • No native Fluent Design
  • Windows-only, no cross-platform
  • Migration to WinUI 3 requires full UI rewrite
Assemblysoft has delivered many WinForms applications and knows how to extract the best performance for your users. We also specialise in migrating WinForms to .NET 10.
WPF
Actively maintained

Windows Presentation Foundation — the gold standard for sophisticated managed Windows applications. Uses XAML to cleanly separate UI from business logic, making it ideal for complex data-bound applications, custom styling, and graphics-intensive scenarios.

Pros
  • XAML + MVVM — clean separation
  • Drag-and-drop designer & Hot Reload
  • Fluent Design via libraries
  • Rich data binding and templating
  • Path to WinUI 3 is straightforward
Cons
  • Windows-only
  • No built-in cross-platform path
We have real-world experience delivering WPF applications still supporting businesses today — from line-of-business dashboards to complex data visualisation tools.
WinUI 3
Modern & recommended

The latest Windows UI framework, decoupled from the OS via the Windows App SDK. Supports C# with .NET and native C++ with Win32. Built for Windows 10/11 with first-class Fluent Design support and the most modern Windows 11 look-and-feel.

Pros
  • Native Fluent Design System
  • Hot Reload for UI development
  • Windows App SDK integration
  • Decoupled from OS update cycle
  • Actively evolving framework
Cons
  • No drag-and-drop UI designer
  • Windows-only, no cross-platform
  • Still maturing — not all APIs stable
Assemblysoft can help you build a WinUI 3 application with robust Fluent Design that makes a genuine impression on your users, ready for Windows 11 and beyond.
Win32 / MFC / ATL
Legacy support

The original native Windows application model. Win32 provides direct OS and hardware access — the choice when you need maximum performance or deep system integration. MFC and ATL layer C++ abstractions on top for more manageable codebases.

Pros
  • Maximum performance ceiling
  • Deep OS and hardware integration
  • C++ and Rust supported
  • No managed runtime overhead
Cons
  • No Fluent Design or .NET
  • No drag-and-drop designer
  • Higher development complexity
Assemblysoft started with pure Win32 and progressed through MFC. We maintain legacy codebases and can modernise your MFC app incrementally to managed .NET targets.
UWP XAML
Legacy — migrate to WinUI 3

Universal Windows Platform targets Windows desktop, Xbox, HoloLens and Surface Hub from a single codebase. Still the only supported native path for Xbox and HoloLens. New projects should prefer WinUI 3 via the Windows App SDK for desktop workloads.

Pros
  • C#, C++ and VB supported
  • Xbox, HoloLens, Surface Hub
  • Drag-and-drop designer & Hot Reload
  • Fluent Design via WinUI 2
Cons
  • Not recommended for new desktop projects
  • Sandboxing limits some integrations
  • Windows-only, no cross-platform
We have delivered UWP applications including Silverlight-era work. We can maintain your existing UWP app and guide a migration to WinUI 3 at the right time.
.NET MAUI
Cross-platform recommended

Multi-platform App UI — a single .NET 10 codebase targeting Windows, iOS, Android and macOS. Supports both native MAUI controls and Blazor Hybrid rendering for teams sharing code with web projects. The preferred choice for any project requiring Windows alongside mobile.

Pros
  • Single codebase: Windows, iOS, Android, macOS
  • Blazor Hybrid for shared web UI
  • .NET 10 — latest runtime
  • Hot Reload across all platforms
  • Access to native APIs per platform
Cons
  • Less rich Windows-specific UI vs WinUI 3
  • Overhead if targeting Windows-only
Assemblysoft builds .NET MAUI apps with Blazor Hybrid for clients who need a single codebase to ship on Windows, iOS and Android — maximising code reuse across platforms.
Not sure which framework is right for your project? We'll help you choose.
Talk to our Windows team

Windows App Development Company with over 25 years developing for the Windows Platform

Based in the United Kingdom, with developers spread across the globe, primarily Western Europe, US and Canada.

Windows Development Expertise

Delivered by Assemblysoft

Over 25 years building Windows desktop applications — from Win32 and MFC through WinForms, WPF and UWP, to modern .NET MAUI and WinUI 3. We bring full-stack .NET context to every Windows project.

25+Years on Windows
7UI Frameworks
.NET 10Latest Runtime
100%UK Microsoft Partner
Business Benefits
High Performance & Responsiveness
  • Native Windows OS access for maximum throughput
  • Offline-first architecture for reliable operation
  • Direct hardware integration where required
Rich User Experience
  • Fluent Design System with WinUI 3 and WPF
  • Complex data grids, charts and visualisations
  • Familiar Windows interface patterns for fast adoption
Enterprise Security & Compliance
  • Windows authentication and RBAC integration
  • Encryption at rest and in transit as standard
  • Meets regulated industry compliance requirements
Seamless Integration
  • REST API and Azure service connectivity
  • SQL Server, Azure SQL and Cosmos DB support
  • Office and Microsoft 365 integration
Scalability & Long-term Support
  • Modular architecture grows with your business
  • Microsoft LTS releases for stable foundations
  • Ongoing maintenance and feature delivery included
Legacy Modernisation
  • Win32, MFC and .NET Framework to .NET 10
  • WinForms and WPF to WinUI 3 or .NET MAUI
  • Incremental migration with zero business disruption
Windows frameworks & technologies we actively use
WPF
WinForms
WinUI 3
.NET MAUI
Blazor Hybrid
Win32 / MFC
UWP / XAML
Windows Services
Console Apps
Windows App SDK
Entity Framework
Azure DevOps CI/CD
Why Assemblysoft?

We started on Win32 — we know Windows from the ground up

25+ Years Platform Depth
From pure Win32 and MFC through every generation of Windows UI framework to WinUI 3 and .NET MAUI. No other UK agency has this depth of real-world Windows delivery history.
Greenfield & Modernisation
We build new Windows applications from scratch and we modernise legacy codebases — migrating MFC, WinForms and .NET Framework apps to modern .NET 10 targets with minimal business disruption.
Cloud-Connected Desktop
We connect Windows applications to Azure backends, REST APIs and real-time data services — giving your desktop app the power of the cloud without sacrificing the native Windows experience.
End-to-End Delivery
Architecture, development, Azure DevOps CI/CD pipelines, ClickOnce or MSIX packaging, and ongoing support — we own the full delivery lifecycle for your Windows application.
High-performance native Windows applications
Legacy modernisation with zero disruption
Cloud-connected architecture on .NET 10
25+ years Windows platform expertise
Start a Windows Project

What is Windows Application Development?

Windows application development is the practice of designing, building and maintaining software that runs natively on the Microsoft Windows operating system. Windows applications include desktop GUI applications built with WPF, WinForms, WinUI 3 or UWP, Windows Services for background processing, console applications for automation and tooling, and cross-platform desktop applications built with .NET MAUI or Blazor Hybrid targeting Windows. Native Windows applications benefit from direct hardware access, offline operation, deep OS integration, complex UI capabilities and the performance of the underlying Windows platform.

Windows Technologies Assemblysoft Delivers

Assemblysoft designs and builds production Windows applications across the full Microsoft desktop stack. WPF (Windows Presentation Foundation) applications with XAML and MVVM patterns using CommunityToolkit.Mvvm for data-bound, testable architectures. WinForms applications for rapid line-of-business tooling and enterprise workflow automation. WinUI 3 applications targeting the Windows App SDK with Fluent Design System for modern Windows 11 experiences. UWP applications for Xbox, HoloLens and Surface Hub alongside Windows desktop. .NET MAUI applications targeting Windows, iOS, Android and macOS from a single codebase with optional Blazor Hybrid rendering. Win32 and MFC native C++ applications for high-performance, hardware-critical scenarios. Windows Services for background processing, scheduled jobs and OS-integrated automation. Console applications in .NET 10 for DevOps tooling and automation scripts.

Legacy Windows Application Modernisation

Assemblysoft specialises in migrating legacy Windows applications to modern .NET targets. Common migration paths include Windows Forms and WPF from .NET Framework 4.x to .NET 10, Win32 and MFC C++ applications to managed .NET with P/Invoke or COM interop boundaries preserved, UWP to WinUI 3 via the Windows App SDK migration path, and .NET Framework Windows Services to .NET Worker Services with hosted service patterns. All modernisation engagements are delivered incrementally to avoid business disruption, using strangler fig patterns where appropriate.

Assemblysoft — Windows Application Development Company, United Kingdom

Assemblysoft is a UK Microsoft Partner with over 25 years of Windows platform delivery experience. The team has built Windows applications for clients in manufacturing, pharmaceutical compliance, financial services, logistics and field service management. Every Windows application is deployed via Azure DevOps CI/CD pipelines with MSIX or ClickOnce packaging. We provide ongoing maintenance, feature development and platform upgrade retainers for all Windows applications we deliver.

Frameworks
WPF, WinForms, WinUI 3, UWP, .NET MAUI, Blazor Hybrid, Win32, MFC
Runtime
.NET 10, .NET Framework 4.8 (legacy support)
Architecture
MVVM, CommunityToolkit.Mvvm, Dependency Injection, Entity Framework Core
Database
SQL Server, Azure SQL, SQLite, Cosmos DB
Deployment
MSIX, ClickOnce, Windows Store, Azure DevOps CI/CD
Location
United Kingdom
Partner status
Microsoft Partner
Industries
Manufacturing, Pharmaceutical, Finance, Logistics, Field Service
Contact intent
hire Windows developer UK, WPF development company, WinForms modernisation, legacy Windows app migration, .NET MAUI Windows desktop
Call Us

+44 (0) 1202 428719

UK · Bournemouth
Visit Us

2 Woodland Walk, Bournemouth

Dorset BH5 1LU, United Kingdom
Email Us

hello@assemblysoft.com

Start a meaningful conversation with us today.

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Assemblysoft are Your Safe Pair of Hands

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