We build, maintain, and modernize custom Windows Forms (WinForms) applications that run mission-critical internal workflows. Because WinForms is still fully supported by Microsoft, we help teams get the most out of the systems they already rely on, taking over legacy codebases, stabilizing and extending them, and advising on if and when a rewrite is worth it.
Customer Reviews
I was astonished that, in such a short period of time, something that other companies had taken months to understand, this company was able to execute. Since then, we have never looked anywhere else. I would never consider another company. This is how much we believe in them.
The other agencies we looked at, frankly, wanted to tell us how great they were. Sembit instead asked a lot of probing questions and provided the kind of consultation that really made us comfortable in hiring them.
It's been excellent every step of the way. The initial conversations were excellent — we had an instant human connection. In addition to being professional, they also had a human touch that's irreplicable.
I've really loved working with them. Sembit always delivers what they say they're going to deliver, in the time they say they'll deliver it. Whenever we have a deadline for a task delivery, the team gives us detailed and frequent updates about their progress. It's been a great partnership.
Sembit's team really took on the mindset of our business which resulted in a better product with thoughtful decisions from developers. We have been able to have healthy discussions about the pros and cons of a design choices which ultimately makes a better product in the long run.
Sembit has over-delivered on their promises at every step of the process. They've come in ahead of schedule and below budget, and they let us know if we are asking for too much. They are clear communicators, and it made a world of difference for our company.
Sembit is capable of taking over WinForms applications that run critical internal workflows. Because WinForms is still supported by Microsoft, we advise organizations to wait on a rewrite until they have a compelling business reason to do so. Our senior team can safely maintain, extend, and stabilize what they already have.
Maintaining a Custom Payroll System
One of our customers has unique revenue sharing and payroll rules, so they rely on a custom payroll system written in C# and WinForms. They asked whether they should rebuild it. After reviewing the system, we advised that a rewrite would be costly without adding meaningful value. Instead, we provide ongoing support and targeted enhancements to keep the system aligned with their evolving needs.
Highlights from this project:
WinForms Ordering System Takeover
Another customer is a parts supplier. Their WinForms system controls ordering and internal workflows tied to a custom backend database. When the original developer retired, they needed a team that could understand the existing codebase and keep their system moving forward. We stepped in, took over maintenance, extended the database, and implemented improvements and integrations with online storefronts.
Highlights from this project:
A Native Windows Camera Dashboard
On rare occasion, we recommend using WinForms for a new internal app. For one customer, we built a native Windows dashboard to display multiple camera feeds for a single operator. WinForms was appropriate because of the libraries needed to interface with the cameras.
Highlights from this project:
These are the situations where teams most often bring us in for WinForms work, from maintaining and extending a mission-critical desktop app to modernizing one that still runs daily operations.
Most WinForms work today is ongoing support for an existing internal application. This often happens when the original developer retires, the original vendor is no longer available, or the company needs more dependable maintenance. We take over the codebase, fix any existing problems, and implement new features as needed. We provide this service for several of our current customers.
Our Oregon-based Team
Projects completed
Years in business
Average Years Experience per Employee
WinForms is not a technology younger developers know, which is why many companies struggle to find a reliable partner for legacy WinForms support. Sembit has been around long enough to have senior engineers who genuinely know older Microsoft stacks. That matters when you need someone who can read the code, understand what was built in 2005 or earlier, and safely make changes without destabilizing a critical business application. This is not theoretical knowledge. We actively maintain WinForms apps for several customers, saving them tens of thousands of dollars in rewrite costs.
If you ever reach a true cutover point, such as a platform limitation or an end of life announcement, we can help you plan and execute a migration. The advantage of working with a team that knows both the older technologies and modern architectures is that we understand the intent of the original code and can translate that into a modernized system that fits your situation.
Tell us more about your custom WinForms development needs. We can help.
Get expert guidance from Nathan Theophanes (Sembit's President) and Shaun Davidson (Sembit's VP) regarding your WinForms project.
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Most WinForms development projects revolve around internal line-of-business systems rather than public-facing software. Because WinForms applications are native Windows executables, they are typically deployed inside a company's network and used for operations such as payroll, inventory management, ordering systems, accounts payable, billing utilities, or internal reporting tools. These systems often start as Access databases or older mainframe tools and are later migrated into C# and WinForms for stability and maintainability. WinForms continues to perform well for these desktop-driven, operations-heavy workflows where speed, reliability, and direct database connectivity matter.
A significant portion of WinForms development today involves legacy support and incremental improvement. Many of our clients have applications originally built in the early 2000s that still run critical business processes. We take over maintenance when the original developer retires, add new features, extend database schemas, and implement small but important tweaks. Because Microsoft still supports the .NET Framework that includes WinForms, many systems remain stable and viable for years with the right engineering oversight.
WinForms projects commonly connect to SQL Server or other enterprise databases to manage structured operational data. We frequently work with systems that evolved from spreadsheets, Access databases, or even older mainframe solutions and were later rewritten into WinForms for better control and scalability. These applications often manage high-value business data such as parts catalogs, order processing, billing rules, or scheduling logic. We extend data models, optimize performance, and build new integrations with backend systems when needed. In some cases, we also create small utility programs that fill gaps between larger ERP systems, giving teams a lightweight but powerful desktop interface for specialized workflows.
Because WinForms is a native Windows technology, it excels at building lightweight utilities and desktop tools that need deep integration with the operating system. We have built tray-based utilities that monitor internal processes, dashboard applications for multi-camera machine monitoring, and custom operational tools that run continuously in the background. These applications can minimize to the system tray, interact with local hardware, and integrate with Windows-level services more easily than web-based applications. For environments that require a dedicated operator console or kiosk-style interface, WinForms provides a stable and performant solution. This makes it particularly effective for manufacturing floors, logistics operations, and controlled internal environments.
WinForms applications may be companion systems to larger enterprise platforms. We have built desktop utilities that extend billing systems, bridge gaps in ERP workflows, and handle complex rule-based logic that was difficult to implement inside a monolithic enterprise product. These projects often begin when an organization realizes their primary system cannot handle a specific workflow cleanly. Instead of replacing the entire ERP, a targeted WinForms application provides a focused solution with direct database access and structured business logic. This approach delivers operational improvements without the disruption of a full enterprise platform migration.
WinForms applications are typically deployed within controlled environments and often integrate with Active Directory or other enterprise authentication systems. Because they are internal executables rather than browser-based tools, they operate inside corporate security boundaries and can be tightly permissioned. We design role-based access controls and user-specific workflows where different departments need different levels of functionality. For companies operating entirely within Windows ecosystems, this native integration simplifies deployment and management. These authentication and deployment patterns make WinForms a dependable choice for internal systems that must remain secure and stable over long time horizons.
FAQs About Our Custom WinForms Development Services
Yes. Many customers do not know the exact technology name, they just know it is a Windows program they run on their PCs. We can take over support, maintain it, and implement changes. We will start by reviewing the codebase and build process to confirm what it is and what it needs. This is a common scenario because WinForms is older and original developers are often no longer available.
It depends on what you'd gain from a rewrite. In most cases rewriting would be a large up-front cost without delivering much value. WinForms is still supported by Microsoft, and if the app is meeting your needs, we recommend you keep it and make targeted tweaks. We can help you perform a cost-benefit analysis based on your requirements.
Yes. This is one of the most common triggers. We regularly inherit WinForms systems and become the long-term support team. This reduces operational risk and ensures the system can keep evolving. In keeping with our standard support practices, we retain multiple staff who are knowledgeable about your particular application.
Most WinForms applications are internal line-of-business apps. They are executables, not web pages, so they are usually used inside a company's intranet and desktop environment. Common examples include ordering systems, inventory tools, payroll utilities, accounts payable, and administrative utilities. WinForms can be used for almost anything, but it is usually chosen for internal operations
Yes. Many WinForms apps connect to internal databases and support integrations tied to business workflows. WinForms is often used as the front end while the real data lives in a database. We can maintain both sides of the system.
We can build WinForms applications when it is the right fit. We have built WinForms tools from scratch when a lightweight Windows utility or internal dashboard was the most practical choice.
Absolutely. We primarily build web and mobile applications for our customers, and would be happy to migrate your WinForms app to a modern platform.
WinForms is older technology, and Sembit has senior engineers who know it well. That matters because maintaining WinForms requires being able to read and safely modify older codebases. Teams that have only been building modern stacks for the last 10 years often struggle with these systems. We can support and maintain WinForms apps today, and if you ever need to migrate off older technologies, we are equipped to understand both the source and the targets.
