Moving to .NET 10: an enterprise modernisation plan for 2026

Why this matters now

As of 30 October 2026, Microsoft states that support for .NET 8 and .NET 9 ends on 10 November 2026. .NET 10 is an LTS release. For applications approaching end of support, upgrading is an operational continuity issue as well as a development task. Check the official support page for changes to the schedule.

Make the running system visible

Inventory the runtime, NuGet packages, authentication, scheduled jobs, reporting tools, external APIs and database version. Map critical journeys such as opening an order, approving it and updating inventory. A successful compilation does not prove that these journeys work. Production settings, file permissions and operational dependencies also belong in the test plan.

Incremental upgrade or rewrite?

If business rules remain sound, updating dependencies and runtime can be a narrower change than rebuilding the product. Where architecture creates access, scaling or maintenance problems, selected modules may need refactoring. Not every modernisation requires microservices. Decide using team capacity, risk, deployment frequency and observability needs rather than architectural fashion.

Design data migration and rollback together

Check whether database changes remain compatible with the previous application version. Rollback is not simply copying old binaries: the previous version must still understand the data. Rehearse backup and restoration. Include permissions, simultaneous edits, uploads and external-service failures in acceptance testing, with named owners for each scenario.

Define completion beyond deployment

Capture baseline error rates, response times, background-job outcomes and critical record counts. Validate with a limited user group and define a monitoring window. Nexus Core Studio plans .NET development and modernisation around system discovery, explicit acceptance tests and operating responsibilities. A runtime change alone is not a promise of better performance.

Related services

• Custom software development
• Maintenance, support & modernization

Further reading: Enterprise AI: RAG, source evidence and access boundaries

Sources and scope

• Microsoft — .NET support policy
• Microsoft — .NET 8 and 9 end of support

Sources checked: 30 October 2026. Implementation steps are general engineering guidance from Nexus Core Studio and should be validated for the organisation and operating environment.

The cover is an AI-generated illustrative scene, not a photograph of a customer project.