For years, bumping an Umbraco version was a matter of updating a few packages. The leap from 13 to 17 is different — for one clear reason: the backoffice has been rebuilt from scratch.
What changed under the hood
Up to and including version 13, the backoffice ran on AngularJS, a framework that has itself been end-of-life for years. With Umbraco 14, that entire admin area was rebuilt from the ground up on modern web technology: TypeScript and Web Components. For anyone managing content that's good news — but it also means custom work doesn't simply carry over.
Where an upgrade gets tricky
- Backoffice customisations — custom property editors and dashboards must be rebuilt.
- Third-party packages — not every plug-in has a version that works with 14+.
- API and model changes — code relying on deprecated APIs needs attention.
- .NET 8 → .NET 10 — the underlying runtime moves up too.
The good news: your content, structure and data simply come along. The work is in the shell around them.
Why a specialist makes the difference
Precisely because this isn't a button you press, experience pays off: spotting upfront which custom work needs rebuilding, which package is a blocker, and in what order to migrate so you're never left without a working site.