New in Symfony 3.3: Deprecated cache clear with warmup

Symfony 3.3 deprecates the warmup part of the cache:clear because it does not work well and it doesn't guarantee that the generated cache is exactly the same as the one that would have been generated via cache:warmup.

New in Symfony 3.3: Simpler service configuration

Symfony 3.3 adds new features to simplify services configuration thanks to the default config options and the interface-based config options.

New in Symfony 3.3: Kernel Build Method

In Symfony 3.3 it will be easier to write applications that don't use bundles thanks to the new build() method added to the Kernel class.

New in Symfony 3.3: Deprecated X-Status-Code

Symfony 3.3 has deprecated the X-Status-Code HTTP header used to set custom status codes when dealing with exceptions.

New in Symfony 3.3: Deprecated the ClassLoader component

Symfony 3.3 has deprecated the entire ClassLoader component because, in the new PHP 7 era, it doesn't provide any significant performance improvement.

New in Symfony 3.3: Asset preloading with HTTP/2 Push

Symfony 3.3 added support for preloading web assets with HTTP/2 Push, a technique that allows web servers to send resources to a web browser before the browser gets to request them.

New in Symfony 3.3: XLIFF linter

In Symfony 3.3 we added a new linter to check the XLIFF translation files.

New in Symfony 3.3: Getter injection

Symfony 3.3 adds a new experimental dependency injection mechanism called "getter injection".

New in Symfony 3.3: Deprecated the autowiring types

In Symfony 3.3, the "autowiring-types" option is deprecated in favor of defining simple service aliases.

New in Symfony 3.3: Import config files with glob patterns

In Symfony 3.3, configuration files can import other resources using "glob patterns" to make them simpler and easier to maintain.