.NET Development

Business software
built on current .NET

We build applications and APIs on current .NET, move older .NET Framework software across, and keep everything on supported versions, so each upgrade is routine, not a project.

Thanks, we’ll be in touch soon.

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You’re in good company

A few of the companies we’ve worked with.

When the upgrade keeps getting put off

Many companies run their core business on .NET software written years ago, on the .NET Framework or on an early version of .NET, one of the releases Microsoft brings out each November. Upgrading always loses to the next deadline. Meanwhile each early version of .NET reaches the end of Microsoft’s support and stops getting security updates, and the .NET Framework, though its recent versions are still supported as part of Windows, runs only on Windows, while Microsoft points new development to current .NET. Each of these is easier to sort out before support ends.

What we build

Each piece starts on a supported version of .NET, with tests, automated checks that run on every change, from its first release, so moving it to the next version is ordinary work.

  • New applications

    Started on the current long-term support version of .NET, the kind Microsoft supports longest, and built to the conventions in Microsoft’s own documentation.

  • APIs

    The entry points other software uses to read and change your data. An API checks who is calling and what each caller may do before it answers.

  • Internal business systems

    The order, stock and approval screens your staff use all day, shaped around how the work actually moves through the business.

  • Moves off the .NET Framework

    Older .NET Framework applications moved to current .NET a part at a time, with each part moved across or rebuilt, as the map below shows.

  • Version upgrades

    From one .NET version to the next, with its packages, code from other teams that it’s built on, brought along. Microsoft calls this a smaller job than leaving the .NET Framework.

  • Connections to other systems

    Linked to the systems you already run, from CRM and ERP to finance, with one system in charge of each detail.

  • Running on Linux and in containers

    Current .NET runs web applications and services on Windows, Linux and macOS, and in Linux containers, so the choice of server is yours.

  • Windows desktop apps

    Desktop apps moved to current .NET, which still runs them on Windows only, or a web version where people need the app in more places.

  • A faster application

    Where the time goes is measured first, in the code, the database and the screen, then fixed in order of what it costs the people using it.

Moving off the older .NET Framework

.NET is Microsoft’s platform for building applications, and it comes in two lines. The .NET Framework is the older one. Its recent versions are still supported as part of Windows and get security and reliability fixes, but it runs only on Windows, and for new development Microsoft points to current .NET.

Current .NET, once called .NET Core, gets a new version every November, and its web applications and services run on Windows, Linux and macOS, and in Linux containers.

For a large web application, Microsoft’s migration guide recommends moving it in parts: a new application is set up in front of the old one and takes over one area at a time, passing everything else back to it, until the old one has nothing left to do. Some parts move across with changes; others have no equivalent on current .NET and are rebuilt.

Where each part goesChoose a part of an older application.

On the .NET Framework

On current .NET

  • Web pages, apps and APIsASP.NET Core
  • Services other systems callCoreWCF
  • Background jobsWorker services
  • Database codeEntity Framework Core
  • Desktop apps, on WindowsWindows Forms and WPF

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Kept on supported versions of .NET

A new version of .NET arrives every November. Each is either a long-term support release, which Microsoft supports for three years, or a standard-term one, supported for two, and patches come every month, on the second Tuesday. The packages your application uses keep schedules of their own.

We keep your application and its packages on supported versions: each upgrade is planned well ahead of the date its version leaves support, tried on a copy with your tests, and only then made live.

Today, .NET 10 is the long-term support version, supported until November 14, 2028, and .NET 8 and .NET 9 both reach the end of their support on November 10, 2026.

Start with a review of your application

The review covers which versions of .NET your application runs on and when each leaves support, its packages, which parts are still on the .NET Framework and whether each moves across or is rebuilt, its tests, where and how it runs today, its slowest pages and database queries, its security basics and how changes go live. You get a written review under three headings, Keep, Fix and Rebuild, and a proposal for the first step.

Nothing built yet? We start from what the application must do at launch and where it will run.

Questions worth asking

  1. Do we have to move off the .NET Framework?

    Not always. Microsoft still supports the .NET Framework as part of Windows, and its own guidance is that most existing applications don’t need to move. Where staying put for now is reasonable, we’ll say so. New work belongs on current .NET, though, often as a new service beside the older application.

  2. Can you move our application to current .NET?

    Yes, a part at a time. The new application is set up in front of the old one and takes over one area at a time while the rest keeps running, and each part moves across or is rebuilt, as the map above shows.

    Legacy Modernization

  3. Which version of .NET should we be on?

    Usually the current long-term support version, which Microsoft supports for three years: today, .NET 10. A standard-term version, supported for two years, suits a team ready to upgrade more often.

  4. Does .NET run on Linux?

    Current .NET does: its web applications and services run on Windows, Linux and macOS, and in Linux containers. The .NET Framework runs only on Windows. So once an application has moved, where it runs becomes a choice, which we make with you.

    Cloud, DevOps & Security

  5. Can you take over our existing application?

    Yes. The review above comes first, so we know which versions it runs on and which parts need care before we change anything, and you agree the order of the work.

  6. Do you build Windows desktop apps?

    Yes. Desktop apps run on current .NET too, still on Windows only, as Microsoft’s guides set out. Where people need the app beyond Windows, a web version can suit better, and we’ll say which.

  7. Can you add tests to code that has none?

    Yes. We begin with tests that record what the application does today, so every change after that, the move to current .NET included, can be checked against them.

    QA & Test Automation

  8. Can you make our application faster?

    Yes. We start with how it performs for the people using it, trace what slows it down, from the screen to the database, and fix the biggest causes first, measuring each fix rather than assuming it.

    Performance & Optimization

  9. Who hosts it?

    Hosting and the platform beneath your application are a service of their own. On current .NET, that platform can be Windows or Linux, with or without containers.

    Cloud, DevOps & Security

  10. How do you keep it secure?

    We keep .NET and your packages on supported versions, with Microsoft’s monthly patches applied. Beyond that, the code gets threat modeling, code review and checks in every build, so security problems are found early.

    Application Security

  11. What does it cost?

    It depends on how much of the application moves across and how much is rebuilt. Before any work starts, you get a written proposal: the scope, the price or rate, and how you pay.

    Pricing

  12. Can we have .NET developers in our own team?

    Yes. We introduce .NET developers matched to your application within 48 hours, working in your time zone, and you decide who joins.

    Hire .NET Developers

Microsoft and Windows are trademarks of the Microsoft group of companies. Webair isn’t affiliated with or endorsed by Microsoft.

Let’s build it better

Tell us which versions of .NET your software runs on and what it needs next, and we’ll propose a first step.

Thanks, we’ll be in touch soon.

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