.NET Modernisation & Upgrades

Keep your .NET applications supported, secure and cheap to run

I've built ASP.NET applications since the first release and ASP.NET Core since version 1. If your business depends on an older .NET application, I'll upgrade it to a supported version, move it to modern hosting and leave it easier to maintain. You won't need to rewrite from scratch.

Start a project

Sound familiar?

.NET 8 and .NET 9 both reach end of support on 10 November 2026, after which they get no security patches
A business-critical app runs on .NET Framework and nobody wants to touch it
Hosting costs keep rising and the app can't move to containers or the cloud
The original developer has moved on and the codebase is a black box

What you get

Upgrade audit: dependency and risk analysis, and a costed migration plan
Incremental migration to .NET 10 (LTS, supported until November 2028)
Automated tests around critical paths before anything changes
Containerisation and a move to Azure, AWS or modern Windows/Linux hosting if needed
CI/CD pipeline so future updates are routine

Ways to work together

Every engagement starts with a small, paid, fixed-price first step. That's where requirements are gathered and the scope and cost estimate for the rest of the work are written, so you know what you're committing to.

Upgrade audit

from £1,500

A report on what needs to change, the risks, and a costed migration plan.

Migration

Estimated in the audit

Delivered in stages, with the app staying live throughout.

Keep-current plan

from £450 / month

Security patches, dependency updates and yearly .NET upgrades.

Further reading: .NET 8 upgrade readiness check: is your application ready for .NET 10? · .NET 8 end of support (10 November 2026): what it means and what to do · Windows Server 2016 end of support (12 January 2027): what it means for your applications · Migrating .NET Framework to .NET 10: a practical guide · Supporting a legacy .NET Framework application without a rewrite · How to audit a .NET codebase you've inherited · What it costs to upgrade, take over or look after a bespoke business system

Common questions

What happens if I stay on .NET 8 after 10 November 2026?

Your application keeps running, but Microsoft stops publishing security patches for .NET 8 and .NET 9. Any vulnerability found after that date stays open, which can also affect Cyber Essentials, ISO 27001, customer security questionnaires and insurance.

Should I upgrade to .NET 9 or .NET 10?

.NET 10. It's a long-term support release, supported until November 2028, while .NET 9 loses support on the same day as .NET 8. Upgrading to .NET 9 now would mean doing the work twice.

What does the .NET upgrade audit cover?

An inventory of your applications, services and scheduled jobs; a check of every third-party package, breaking change and hosting dependency against the target version; the risks; and a costed, staged plan for the upgrade. You keep the written report whether or not I do the work.

How much does a .NET upgrade cost?

It depends on the size of the application, its dependencies and how much automated testing it already has. The upgrade audit, from £1,500, produces a costed plan, so you know the cost before committing to the work. Moving from .NET 8 to .NET 10 is usually a much smaller job than migrating from .NET Framework.

Will my application stay live during the upgrade?

Yes. The upgrade is done and tested in a separate environment, then released in stages with a rollback plan, so your users keep working throughout.

Can you upgrade a .NET Framework application?

Yes. .NET Framework applications can usually be migrated to .NET 10 in stages, without a rewrite and while the application stays live. The audit identifies which parts can move as they are and which need changes.

Do we need to rewrite the application?

Rarely. A rewrite is expensive and risky, and it throws away years of business rules that already work. Most applications can be upgraded and modernised in place.

Have a project in mind?

Tell me what you're trying to achieve, and I'll reply as soon as I can to say whether it's a fit and what the fixed-price first step costs.