Upgrading a Symfony application to PHP 8.4 doesn't have to mean rewriting half the codebase.
For applications that have been running in production for years, the real challenge is deciding what to modernize, what to keep, and how to move forward without turning a technical upgrade into a long and risky project.
PHP 8.4 brings useful features such as property hooks, asymmetric visibility, native lazy objects, and the #[Deprecated] attribute. It also integrates particularly well with recent Symfony versions.
But a successful migration is less about adopting every new language feature and more about:
checking dependencies and platform requirements
